Spring 2017 Tester Symposium Abstract Listing
1:45 Introductory Remarks - Dr. Andrew Taylor
2:05 PM Session I Chaired by Dr. Amy Moran
The effect of temperature and pH on respiration and photosynthesis rates in Gracilaria salicornia, an invasive red alga
Megan Onuma and Celia Smith
Despite the relative wealth of studies examining how global climate change will affect corals and other calcifying organisms, there is a lack of information on how global climate change will affect macroalgae. Macroalgae make up an important part of the coral reef ecosystem, providing food and oxygen for reef inhabitants. Understanding how their ecology may change over the next century will be useful knowledge for conservation management. This study focuses on how the interactive factors of temperature and pH affect the respiration and photosynthesis rates of Gracilaria salicornia, an invasive alga in Hawai’i originally from the western Pacific Ocean. Using an outdoor, flow-through seawater system with natural sunlight, we exposed G. salicornia thalli to different temperatures and pH values using a full-factorial design. At the end of a three-day exposure to treatment conditions, respiration was measured using oxygen evolution methods and photosynthesis was measured using Jr. PAM to obtain rapid light curves. Each response variable was analyzed independently using multiple regression models. The models suggest that nighttime temperature and the square of nighttime temperature had significant effects on respiration rates (p<0.03 and p<0.04, respectively). Our analysis indicates that pH had a slight but significant effect on ETRmax (p<0.05). These analyses indicate an increase in respiration and photosynthesis rates under climate change conditions, though further research will be needed to determine how these metabolic increases affect the growth and distribution of the organism.
Some of the evolved behaviors, which show significant advantages in survival and/or mating in a particular environment, present striking similarity to human psychiatric behaviors. This reminds us that ‘adaptive’ or ‘maladaptive’ can be context dependent, and such behavior may serve as a model for behavioral adaptation as well as a platform to discover new treatments for human psychiatric disorders. The Mexican blind cavefish, Astyanax mexicanus, show an intense behavioral adhesion to water vibrations between 30 to 40Hz, called vibration attraction behavior (VAB). In the dark environment, VAB showed strong advantage in prey capture. On the other hand, this behavioral adhesion is thought as a proxy of the adhesion to a particular stimulus seen in autistic patients. VAB is regulated by the mechanosensory lateral line system (LLS) that is composed of hair-cells, and those at the eye orbit were especially shown as the major sensory receptor for VAB. However, it is unknown if this LLS at the eye orbit regulates behavioral adhesion at 30-40 Hz. Here we tested the reduction of their VAB tuning by ablation of the LLS units at eye-orbit. We measured VAB against the vibration frequencies at 0, 10, 20, 30, 40 50, 80 and 100 Hz in both before and after ablation. Right after each set of VAB assay (before or after ablation), we imaged the LLS units with a vital dye, DASPEI, to monitor the ablated LLS units. We are currently analyzing data and will discuss the results.
Expression of selected autism genes in Astyanax mexicanus
Nicolas Cetraro, Masato Yoshizawa, Lillian Tuttle, Alexander Settle, Courtney Passow
Opsins are proteins classically known for forming the key light-sensing molecules responsible for the function of binocular and pineal eyes. Recent studies, however, showed opsin expression in deep-brain of fish, suggesting light-sensing function in these tissues. Interestingly, changes in light conditions induced activity shifts in the blind Astyanax cavefish -- calmer in the dark and more active in the light -- suggesting extraocular opsin activity. In zebrafish 42 opsin genes in have been identified and are expressed in many tissues including: brain, eye, gut, heart, liver, muscle, pineal, skin and testis. Functional roles for some extraocular photoreceptors have been demonstrated in zebrafish deep-brain (phototaxis in darkened environment) and the pineal gland of cavefish larvae (shadow response). Here, we aimed to determine the opsin profile of A. mexicanus and explore the expression differences between cave and surface morphs in different tissues: telencephalon, tectum, pineal, basal brain, eye, and skin. A bioinformatics survey of the A. mexicanus genome revealed 29 orthologs of the 42 zebrafish opsins, representing 16 opsin classes thus, majority of teleost opsin classes are covered in the current genebuild. Tissue samples from the retina, pineal, telencephalon, tectum, cerebellum, and deep-brain were dissected from adult surface and cave fish. Using qPCR, we detected high expression levels of multiple opsins in the cavefish pineal, implicating the pineal as a key tissue in cavefish light-dependent activity. We plan to perform CRISPR/Cas9 and/or pinealectomy to test the involvement of opsin genes and pineal for the light-dependent activity observed in cavefish.
Antarctic sea spiders (class Pycnogonida) have been used to test the oxygen hypothesis of polar gigantism, which states that the low metabolic oxygen demand of Antarctic ectotherms allows them to achieve larger body sizes. The mechanics of oxygen diffusion in pycnogonids are governed by the pore area and thickness of their cuticles, with larger spiders generally having thicker cuticles to support their body mass, and consequently higher porosity to facilitate oxygen transfer. In this study, we quantify the changes to a sea spider’s pore area and cuticular thickness that occur across ontogeny. We examined the cuticle porosity, thickness and mass of 32 Antarctic pycnogonids from four species in two families, ranging in body weight from 0.032g to 2.33g. Our data show that the porousness of the cuticle increases with mass in the genus Colossendeis, but this trend was not seen in Ammothea. We also observed that these two genera had different pore morphology. Our findings suggest that family-level differences in cuticle structure and development may play a role in oxygen diffusion, metabolism and body size in Antarctic pycnogonids.
2:45 PM Session II Chaired by Dr. Masato Yoshizawa
Tripneustes gratilla is a biologically and economically important shallow water sea urchin. With a broad species distribution across multiple ocean climates, the functional genomics of this animal are of interest to the naturalist and aquaculturist alike. The localization and timing of differentially expressed genes can highlight unique functional roles. To this purpose, gene expression profiles of an adult female and male T. gratilla were quantified for three distinct tissues: gonadal, neural, and epidermal. An expression profile was similarly generated for approximately 1,000 plutei larvae. Transcript abundance estimates reveal unique gene expression profile differences between tissues, sexes, and life stages. Furthermore, distinct gene splicing is found to underlie some key profile differences.
Y chromosome is present only in males and encodes genes important for male fertility. Previously, we demonstrated only two Y-encoded genes are required to make a male mouse able to reproduce with assisted reproduction technologies (ART): testis determinant Sry and spermatogonial proliferation factor Eif2s3y. Subsequently, we have shown that the function of these two genes can be replaced by transgenic overexpression of their homologues, Sox9 and Eif2s3x. Males with 2 (XEif2s3yOSry), 1 (XEif2s3yOSox9 and XOSry,Eif2s3x) and no (XOSox9,Eif2s3x) Y genes produced haploid gametes and sired offspring after ART but had abnormal testicular epithelium and interstitium.
We hypothesized that testicular abnormalities observed in males with these transgenics originated from altered pro-gonadal signaling in genital ridges (gonadal precursors) at the time of sex determination. We generated timed-pregnancies, collected fetuses at 12.5 dpc (days post coitum), identified genotypes by PCR/qPCR, dissected and evaluated genital ridges, and quantified transcript expression.
The expression of male pathway factors (Fgf9 and Amh) was decreased in transgenics when compared to XY. Sry-to-Sox9 substitution in the context of Eif2s3x and Eif2s3y-to-Eif2s3x substitution in the context of Sry had no effects. However, Sry-to-Sox9 substitution in the context of Eif2s3y and Eif2s3y-to-Eif2s3x substitution in the context of Sox9 resulted in altered Fgf9 and Amh levels. The observed differences were due to severe depletion of Fgf9 and Amh in XEOSox9 males, which scored lower when compared to all other genotypes. The analyses of genital ridges morphology and anatomy and other expression analyses are ongoing and results will be presented at the symposium.
Stability of the developmental process is key in maintaining an ‘adapted’ species in a given environment, but it could also reduce the chance to adapt to the novel environment. The Mexican tetra, Astyanax mexicanus, is composed of two morphs; the cave dwelling and surface dwelling forms, which have both evolved from a surface dwelling ancestor millions of years ago. Through evolution in the perpetual dark and food sparse cave, cavefish show a larger number of the mechanosensory superficial neuromasts than that of the surface fish. These neuromasts are important for the cave-adapted food foraging behavior, rheotaxis, and schooling. To test the developmental robustness of this sensor, we pharmacologically inhibited the endothelin signaling, which perturbs the cranial bone formation, thus, indirectly inducing the development of more superficial neuromasts. After 5 times of repeated experiments, we found that the neuromast number significantly increased more in cavefish than in surface fish, suggesting that the cavefish may have evolved a developmental flexibility in their mechanosensors in order to adapt to the novel environment. We are further exploring the central neural projection of each neuromast cluster, and relationship between membranous bone formation and the budding process of superficial neuromast.
Gut biota is regulated by gut morphology, gut homeostasis and diet. Contrarily, gut biota is critical in regulating intestinal development, gut homeostasis, host genetics and diet. Astyanax mexicanus is a species composed of cave-dwelling morphs and their ancestral type, surface- dwelling morphs who were trapped in caves millions of years ago depriving them of light and their original food source. Surface-dwelling morphs shifted their diet from small fish to a more restricted diet of rotten organic matter, bat guano, and soil crustaceans. Despite the diversification, they remain interfertile, allowing us to apply genetics to investigate the gut and gut biota evolution. Here, we perform genetic analyses on gut morphology, gut biota, and fatty acid composition by using cave fish, surface fish and F1 hybrids. One month after the larval stage, the three morphs were fed three diets: nutrient-poor spirulina algae, nutrient-rich brine shrimp and bat guano. Cave fish gut morphology showed significantly less pyloric caeca, longer microvilli, and a wider gut diameter than surface fish. Analysis by 16S ribosomal RNA sequencing of the gut biota revealed surface fish and cave fish have significantly different gut biota and F1 hybrids are an intermediate between them. Surprisingly, gut biota is stable in each group regardless of diet, suggesting a major involvement of host genetics. We are currently investigating the relationship between gut morphology, gut biota and fatty acid composition, the major nutrient that symbiotic microorganisms provide, affecting dynamics of synapses and myelin sheaths. In addition, we will be reporting preliminary results.
Augmented Reality (AR) technology uses computer generated three-dimensional (3D) images to permit spatial visualization of objects in virtual space. Since understanding of the spatial relationships between neighboring anatomical structures serves as a foundational skill required by any health-related profession, the ability to visualize structures in 3D space is especially important for Anatomy students.
Recently, in the attempts to investigate the usefulness of the AR presentation in the undergraduate Anatomy and Physiology classrooms, we introduced this technology to PHYL 141L students at UH Mānoa. For this initial assessment, we focused on the osteology section of the course where students were instructed to identify human bones and bony landmarks using two-dimensional images (2D), the AR osteology module (3D), and real bones (3D) to complete laboratory assignments. After the lab, students were asked to complete an online survey to evaluate the use AR technology versus traditional learning tools. This investigation was not a validated study, but rather a preliminary survey seeking to determine whether it would be useful to expand and further develop AR educational modules for undergraduate students. Based on student feedback, the ability to manipulate anatomical structures in 3D space yields more profound learning experiences; and AR technology is a great alternative when physical models are not available. Overall, we found that majority of students (68%, n=205) favored AR assisted learning as an effective and useful addition to their current resources, and would be willing to use it to study other anatomical systems.
9:00 AM Session III Chaired by Dr. Amber Wright
The precise nature of elasmobranch magnetic field perception has remained an unanswered question for some time. Recent studies lab based studies using both sharks and rays have helped to elucidate the parameters of magnetic field perception, and have cast more light on the mechanisms by which this is done. However, the ability to perceive a stimulus, or physically respond to a stimulus does not confer functional use of that ability. Scalloped Hammerhead sharks have been suggested to navigate via geomagnetic topotaxis – by which sharks may navigate to a specific location through discrimination and recognition of local gradients in the geomagnetic field. Here we present results to date of behavioral choice experiments designed to demonstrate the functional capability of Scalloped Hammerhead sharks to locate a specific magnetic structure given a range of options. We further discuss putative magnetic field receptor structures involved in behaviors observed during our experiments.
Habitat-based species distribution modelling of the Hawaiian deepwater snapper- grouper complex
Zack Oyafuso, Jeffrey C. Drazen, Cordelia H. Moore, Erik C. Franklin
Deepwater snappers and groupers are valuable components of many subtropical and tropical fisheries globally and understanding the habitat associations of these species is important for spatial fisheries management. Habitat-based species distribution models were developed for the deepwater snapper-grouper complex in the main Hawaiian Islands (MHI). Six eteline snappers (Pristipomoides spp., Aphareus rutilans, and Etelis spp.) and one endemic grouper (Hyporthodus quernus) comprise the species complex known as the Hawaiian Deep Seven Bottomfishes. Species occurrence was recorded using baited remote underwater video stations deployed between 30-365 m (n = 2381) and was modeled with 12 geomorphological covariates using GLMs, GAMs, and BRTs. Depth was the most important predictor across species, along with ridge-like features, rugosity, and slope. In particular, ridge-like features were important habitat predictors for E. coruscans and P. filamentosus. Bottom hardness was an important predictor especially for the two Etelis species. Along with depth, rugosity and slope were the most important habitat predictors for A. rutilans and P. zonatus, respectively. Models built using GAMs and BRTs generally had the highest predictive performance. Finally, using the BRT model output, we created species-specific distribution maps and demonstrated that areas with high predicted probabilities of occurrence were positively related with fishery catch rates.
Ocean warming threatens coral reef ecosystems by disrupting the coral-alga symbiosis and causing coral bleaching. Recovery from bleaching is essential for the persistence of coral reefs, however bleaching recovery among coral taxa and reef environments is poorly understood. We examined bleaching and 3-months post bleaching recovery in Montipora capitata and Porites compressa that either bleached or did not bleach during a 2014 bleaching event at two reef locations in Kāne‘ohe Bay, O‘ahu. We measured changes in biomass, photopigments, and nutritional provisioning as inferred from stable isotopes. Chlorophyll a and c2 recovered faster in P. compressa than M. capitata at both reef sites, and P. compressa consistently had more biomass than M. capitata regardless of bleaching state or sampling period. However, both species lost 30 – 50 % of their biomass while recovering from bleaching. During thermal stress, the M. capitata holobiont (coral+symbiont) biomass d15N differed between reef sites and d13C was more depleted in non-bleached corals. Conversely, P. compressa biomass d15N and d13C did not differ among physiological states or reef sites. During recovery, M. capitata showed a site-specific reliance on heterotrophic nutrition independent of previous bleaching history, and P. compressa appeared to remain autotrophic but exhibited differences in holobiont d13C among sites. These data show thermal stress reduces biomass in both bleached and non-bleached corals, and nutritional modes during bleaching recovery are context dependent with differences between species and reef locations.
Lacking the ability to relocate in response to environmental stressors, sessile organisms, such as corals, rely on different strategies to survive. Scleractinian corals participate in an obligate symbiosis with single-celled dinoflagellates in the genus Symbiodinium. Rising sea surface temperatures have increased the incidences of coral bleaching — when the algae are expelled from the host — worldwide, which has led to massive coral die-offs. However, different types of Symbiodinium vary in their responses to stress, and while some corals associate with only one type of algae, others associate with multiple clades. In Kaneohe Bay, the coral Montipora capitata, associates with symbionts in clade C (bleaching susceptible) or clade D (bleaching tolerant) or both (at the species and colony level). The dynamic and diverse structural formations of M. capitata provide specialized microenvironments that may play a role in the holobiont’s response to stress. We hypothesize that there is significant variability in Symbiodinium clades and densities in M. capitata across individual colonies. Here we examine the micro-landscape using qPCR and ITS2 sequence diversity through 1) landscape tissue sampling (>50 samples/colony) of plates and branches in 20 colonies of M. capitata in Kaneohe Bay, and 2) mapping sequence data to 3D-images of colonies to assess the relationship of spatial variability to factors such as irradiance, flow, and structural architecture. Assessing the landscape variability of Symbiodinium is a necessary step in examining the ecological advantages that symbionts contribute to the holobiont’s ability to acclimatize and adapt to future climate conditions.
Traditional Hawaiian fishponds (loko iʻa) are marvels of ancient aquaculture that can provide a sustainable and pragmatic solution to sustainability challenges and biosecurity concerns in the face of climate change. Fishponds are a model of low-impact, culturally significant, and sustainable mariculture practices that could be transferred to other island cultures. Since fishpond management focuses on the cultivation of herbivorous fish such as threadfin (moi), mullet (ʻamaʻama), and milkfish (awa), the removal of the fish that prey upon them has been a longstanding and necessary practice. While only a handful of fishponds are still in use today, some, such as Heʻeia fishpond on the windward side of Oʻahu, have transitioned from structural restoration to a phase of food production. Community fishing days provide local fishers the opportunity to utilize a traditional resource and to assist in the removal of predatory fish. We investigate the population dynamics and diet of the three main predatory fish species in Hawaiian fishponds: Caranx melampygus (omilu), C. ignobilis (papio), and Sphyraena barracuda (kaku). Our overarching goal is to provide meaningful scientific results to managers of Hawaiian fishponds that support sustainable food production through the utilization of mark- release-recapture methods, catch per unit effort (CPUE) data, and gut content analyses. Our results will specifically benefit the community of fishers, seafood consumers, and caretakers of Heʻeia fishpond, as well as other fishponds throughout the islands.
Corals host a community of symbiotic algae (Symbiodinium) whose diversity and abundance fluctuate under different conditions, influencing corals susceptibility to bleaching and resistant to climate change. Bleaching reflects the breakdown of this symbiotic association, and may lead to host death or, corals may be able to recover, by acquiring new symbiont algae from the environment. Symbiodinium can be found in reef waters, sediments and in other hosts and may vary in composition, influencing symbiotic assemblages in corals by mediating supply and dispersal. A metacommunity framework, in which an array of local communities is connected by dispersal, may provide insights into the drivers and scales of Symbiodinium community assembly in different compartments on the reef. It is thus critical to understand how Symbiodinium free-living communities and community in different host species in reef habitat compartments are structured, which have up to date received little attention. I propose to investigate the Symbiodinium metacommunity dynamics in different reefs in Kaneohe Bay, by identifying the Symbiodinium composition in sediments, water column, corals and in other hosts presents in the reef (i.e. Cliona sponges, Cassiopeia spp.). I will use ITS2 and qPCR to identify the Symbiodinium types and abundance in each reef compartment. The Symbiodinium composition in different reef compartments will be compared to the Symbiodinium community composition and abundance in corals, along with water temperature and coral’s bleach history. Results of this study will provide valuable insights on Symbiodinium availability for corals in the context of climate change.
Monogamy is not restricted to highly social vertebrate animals, such as birds, mammals, and humans; in fact, monogamous mating systems are known in fish, crabs, beetles, and shrimp. Research, primarily on vertebrates, has revealed that socially monogamous animals exhibit a range of genetic mating systems, from genetic monogamy to high rates of multiple paternity. I observed patterns of mating and egg mass production in a socially monogamous, simultaneous hermaphrodite, the pulmonate limpet Siphonaria gigas. S. gigas inhabits the rocky intertidal zone of the tropical Eastern Pacific, and individuals live in pairs with their shells touching. Individuals occupy fixed positions on the rock called home scars, which they leave only during ebbing tides to forage and mate; thus, their movement is constrained spatially and temporally by the tides. Through observations of a Panamanian population of S. gigas over multiple reproductive cycles, I found that paired individuals have greater reproductive output than solitary individuals. However, I also observed some extra-pair mating. A genetic paternity analysis will be performed to determine whether S. gigas is genetically monogamous, with paired individuals obtaining sperm only from their partners, or whether sperm from several different males are used to fertilize each egg clutch. Since S. gigas lacks characteristics typically associated with monogamy (parental care, territoriality, and mate- guarding), pairing in S. gigas may point to alternative mechanisms for the evolution of monogamy, such as environmental constraints on mate access.
10:45 AM Session IV Chaired by Dr. Bob Thompson
Acacia koa (koa) is an economically valuable timber wood tree playing an important role for Hawaiian culture and ecology. The wood color of koa can range from blond to dark red while its grain figure ranges from plain to curly. Given that koa populations are highly heterozygous and heterogeneous due to cross-pollinating nature, there is no current screening method to select seedlings for superior wood quality. Proanthocyanidins (PA), a subclass of tannins, are shown to be involved in wood quality. The goal of this study is to quantify PAs and identify PA biosynthesis genes as a biomarker for wood color. PA biosynthesis genes: dihydroflavonol reductase, anthocyanidin synthase, anthocyanidin reductase, and leucoanthocyanidin reductase in koa were identified and isolated. To correlate wood color, PAs, and expression of PA biosynthesis genes, koa seedlings expressing hues of green to red were compared from Hawai’i, Oahu, Kaua’i, and Maui. Folin-Ciocalteau analysis and acid butanol assay showed that Maui leaf (red hue) contained the highest total tannin and PA content. qRT-PCR analysis of Maui stem showed upregulation of PA biosynthesis genes compared to Kaua’i and Oahu. Phenotypic variation of leaf, stem, and root was assessed within koa seedlings from Maui and Oahu that showed total tannin content ranging from 0.05-8% and PA content ranging from 0.11- 5%. Characterizing proanthocyanidins as a biomarker for wood quality will be useful as a rapid screening method among progenies of different families in koa improvement programs. This research was supported by the USDA NIFA McIntire project HAW05031-M, managed by CTAHR.
The Hawaiian Islands are the most isolated archipelago on earth; all species that arrived and successfully colonized this new landscape did so given their ability to survive long distance dispersal. One genus that was most likely dispersed by birds is Isachne (Poaceae). There are two native species of this grass represented in the Flora of Hawai‘i. A previous taxonomic study noted these species, I. distichopylla and I. pallens, had morphologies near two found in Java. Subsequent morphological and molecular studies have neither supported nor refuted this claim. This study will examine the phylogenetic relationships between the taxa found in Hawai‘i and Java, along with species from Southeast Asia, North America, Africa, and the Indian Ocean. Sequences from two chloroplast, and one nuclear region will be used to reconstruct a phylogeny with maximum likelihood and Bayesian inference. Our results show that I. distichophylla and I. pallens for a distinct clade that is sister to a Southeast Asian clade. Both of these clades arose from a single ancestor that was African in origin. The preliminary work presented here is significant because it is contrary to the general trend of ancestral dispersal from Southeast Asia to Hawai‘i.
The genus Plumeria L. is comprised of plants that are horticulturally important for their medicinal and ornamental properties. The seven species included in the current description of the genus are solely based on morphological variation in dried herbarium materials. Using morphological characteristics to identify species is often problematic, due to environmental effects on phenotype. Furthermore, invalid or unverified names are used among collectors, and unconfirmed or mislabeled specimens exist among botanical collections. Thus, molecular markers would be an extremely valuable additional tool to distinguish and verify Plumeria species in collections, but useful markers must first be identified. The objective of this study is to identify DNA regions that will clearly and consistently distinguish species differences in Plumeria. A portion of the chloroplast matK gene, chloroplast intergenic spacer regions psbJ- petA, rpl32-trnL, and trnH-psbA, and the nuclear ITS 2 region were tested for their ability to distinguish Plumeria species collected from local, national, and international sources. Single and multiple marker sequence data sets were subjected to neighbor-joining, maximum parsimony, and Bayesian analyses. Analyses of individual regions indicated that intergenic spacer regions, characterized by high interspecific variation and low intraspecific variation, were better able to separate Plumeria species than matK and ITS 2. The concatenated data set of five regions successfully resolved seven out of the eleven putative Plumeria species tested. Analyses using the concatenated data set may have revealed a cryptic species, while also identifying synonymous taxa. These regions can now be used to infer low-level phylogenetic relationships within the genus Plumeria.
Medicinal plants play a critical role in ecosystems, economies, and societies around the world. However, there is currently limited understanding of why people use some plants medicinally and not others; one hypothesis is that plant accessibility and abundance increases likelihood of medicinal use. Yet, the handful of studies that directly test this availability hypothesis have produced mixed results, which may be due to limitations in the size and selection of human and environment samples. Our research rigorously evaluates the availability hypothesis by surveying four subsistence villages in Solomon Islands using interviews with every adult (315 participants), and assessing plant availability using 50m2 Braun-Blanquet cover-abundance survey plots 0-2km from the center of each village (160 plots total) in a systematic random sampling scheme. Results show that species distance, abundance, and maturity have different effects on medicinal plant knowledge. By testing how plant availability affects medicinal plant knowledge, this project clarifies the processes of cognition and learning, and informs new approaches for biocultural conservation.
1:15 Session V Chaired by Dr. Megan Porter
The fundamental molecular unit of vision is the opsin, a gene that encodes a protein that, when bound to a chromophore, forms the light visual pigments of the retina. There is tremendous diversity in opsin repertoires. Direct connections between opsin expression and quantitative behaviours are rare.
Fish have large opsin repertoires, and to understand why, we characterized the visual system of the starry flounder (Platichthys stellatus). Juvenile starry flounder express eight visual opsins in the retina. We held starry flounder in aquaria for six weeks in either broad-spectrum sunlight or green-filtered light and predicted a change in opsin expression. We measured opsin expression and tested visual performance by quantifying the camouflage response to a variety of colourful checkerboards. Opsin expression was different based on light environment. Surprisingly, this difference was lost after only three hours under white LED illumination. Image analysis of camouflage response suggests fish with more UV- and blue-sensitive opsins detect greater colour-contrast on blue-green checkerboards.
We are also studying vision in deep-sea oplophorid shrimp that are capable of producing bioluminescent secretion to deter or distract predators. Some oplophorids also possess bioluminescent organs (photophores) in their cuticle. Species capable of both forms of bioluminescence (secretion and photophore) possess unique visual systems, involving multiple opsins presumably for colour vision. We predict features of the oplophorid visual system function to discriminate between the two types of bioluminescence. Furthermore, preliminary data revealed genes associated with phototransduction are expressed in the photophores suggesting perhaps they “see” with these bioluminescent organs.
The egg masses of the Opistobranch gastropod Phestilla sibogae were examined for the presence of symbiotic bacteria. The complex egg masses produced by P. sibogae consist of individually encapsulated eggs embedded within a gelatinous layer and surrounded by a tough outer coat. This outer coat weakens during the 7 - 8 days required for veliger larva development.
By the time that the veliger larvae are ready to hatch, this coating has significantly weakened allowing the veliger larvae to break out of their capsules and escape the egg mass becoming planktonic. Bacteria located internally and externally within egg-masses of P. sibogae may contribute to the protection and embryotic development of these veliger larvae and may also contribute to the breakdown of the gelatinous matrix of the egg-mass. As a first step in determining the role that the bacterial community may have in this process, I used confocal microscopy to quantify bacterial densities both on and within the egg masses over the time- course of larval development. Culturable strains of bacteria from the external surface, as well as, embedded within the egg matrix were isolated using standard bacterial culture techniques and then identified using 16s rDNA sequencing. These data will help to identify important bacterial members of the microbiome found surrounding and enclose in egg masses of P.sibogae that may be responsible for aiding in both development and hatching.
Each winter, thousands of humpback whales (Megaptera novaeangliae) migrate from their high latitude feeding grounds in Alaska to mate and calve in the shallow tropical waters around the Main Hawaiian Islands. Population estimates suggest that up to 10,000 animals winter in Hawaiian waters, making up more than half of the total North Pacific stock. However, in the 2015/16 season, anecdotal reports from commercial operators, researchers, and citizen- science whale counts tell of an unusually low number of whales compared to previous years off the island of Maui. To examine this issue, data from long-term passive acoustic monitoring with autonomous Ecological Acoustic Recorders (EARs) during the 2014/15 and 2015/16 seasons at three shallow-water sites off the west and south-west coasts of Maui were analyzed using male chorusing levels as a proxy for relative whale abundance. Root-mean- square sound pressure levels (SPLs) were calculated to compare low frequency acoustic energy (0-1.56 kHz) between both seasons. Our results showed that despite a similar onset of the season and similar overall trend reflecting the migratory pattern of humpback whales, SPLs remained lower than in 2014/15 throughout the season on all three sites, suggesting that the number of singing males was indeed lower during the 2015/16 season off west Maui and that future monitoring is warranted.
The false killer whale (Pseudorca crassidens) is a globally distributed species found in temperate and tropical waters. The Hawaiian Archipelago is home to three genetically-distinct populations with overlapping distributions: two insular populations, one within the main Hawaiian Islands (MHI) and the other within the Northwestern Hawaiian Islands (NWHI), and a broadly distributed pelagic population. The mechanisms that create and maintain the separation between these populations are unknown, but previous studies have shown that the acoustic diversity of a species may reflect their genetic differences. The goal of this study is to determine whether the frequency modulated tones, or whistles, produced by individuals in each population are distinguishable from each other. To test this theory, time-frequency measurements of whistles from all populations were collected and used to build a classification model to predict the populations based on their whistle characteristics. Whistle data from 13 MHI, 11 NWHI, and 7 pelagic acoustic detections were included in a Random Forest classification model. Classification results were affected by the sampling methods used when selecting the whistle data for the model. Overall, the MHI whistles had the highest correct classification scores compared to the NWHI and pelagic whistles, despite sampling methods. The biological implications of these results will be discussed along with the applications of this whistle classification tool to acoustically monitor this species and better understand each population’s distribution.
The bluntnose sixgill shark (Hexanchus griseus) is a large bodied shark that inhabits cold waters around the world, staying at deep depths in tropical regions. They exhibit diel vertical migration, swimming at depths deeper than 500m with temperatures below 7 ̊C during the day and at night swimming between 200-300m with temperatures around 15 ̊C. A recent study has shown that deep-water sharks such as the bluntnose sixgill have positive buoyancy in deep habitats and exert greater effort to maintain a given swimming speed during descents, whereas they are able to glide up the water column during ascents. It is hypothesized that this positive buoyancy may allow deep-water sharks to conduct upward migrations when their body temperatures are coolest, and swimming activity is reduced, after spending the day in deep cold water. To test this, bluntnose sixgill sharks were equipped with instrument packages designed to simultaneously measure internal (core body) and external (ambient seawater) temperatures, and collect swimming activity data via tri-axial accelerometers. The data recovered from these devices explore the hypothesis that bluntnose sixgill sharks utilize positive buoyancy to migrate up the water column when their muscle temperatures are at their coolest. This study will help further characterize how deep-water sharks utilize positive buoyancy for diel vertical migration.
3:00-5:00 Poster Session
Mastigias, the ‘golden’ jellyfish, is distributed throughout the Indo-Pacific. Specimens are identified routinely as Mastigias papua, although eight species were described historically, and molecular analyses evince at least three phylogenetic species. Understanding species diversity in Mastigias has become a priority because of its growing relevance in studies of boom-bust dynamics related to environmental change, cryptic species, local adaptation, parallel evolution, and peripatric speciation. However, species delimitation and identification are inhibited by a dearth of type specimens for most species, including M. papua. We address these issues by resampling Mastigias from the type locality, as well as in the Philippines, and by comparing cytochrome c oxidase subunit I and up to 34 morphological characters of 268 Mastigias specimens from surrounding regions in the Indo-Pacific. We also gathered data from the historical descriptions of the eight species of Mastigias to estimate the identity of the two other currently revealed clades. Using this integrative taxonomic approach, we re- describe Mastigias papua as endemic to the tropical western Pacific islands (including Papua, Palau, Enewetak) and designate a neotype and two paratypes for the species. Additionally, based on morphological similarity and geographic overlap, we identified a second clade as M. albipunctatus (from Japan, Komodo, Berau and Philippines) and a third clade tentatively as either M. andersoni or M. ocellatus. This study highlights the benefits of combining resampling of type localities, molecular analyses, traditional descriptions, and statistical analyses of morphological variation in systematic studies, and the potential to increase understanding of evolutionary patterns and processes in Scyphozoa.
‘Opihi ‘alinalina also known as the yellowfoot limpet (Cellana sandwicensis) is a cultural delicacy in Hawai’i. Annual harvest declined from 68,000 kg to 5,000 kg since the turn of the 20th century. Demand from both commercial and cultural entities spurred the need for restoration aquaculture. We aimed to design a novel broodstock tank system, as well as to control maturation and spawning with diet and hormone. Animals were collected from Manana Island with 90% survival and were tagged, measured, and stocked into two tanks. The broodstock tanks maintained approximate surface area of 3958.41 cm2 above water and 1696.46 cm2 below water, simulating the lower intertidal environment. Tanks were supplied flow via an overhead, irrigation spray nozzle at 15 L/min for stimulation and aeration. To control maturation using a diet, treatment 1 was offered a grow-out diet leveled at 40% protein from fishmeal, soybean meal, and krill meal. Treatment 2 was offered a similar diet, with supplementation of arachidonic acid at a ratio of 0.7 (ARA: EPA). Based on gonadosomatic index (GSI) measurements, there was no effect of diet on maturation (P > 0.05); and we suspected environmental cues influenced gametogenesis. Synchronous spawning was induced by injecting animals with a 250 μg/g BW priming dose of salmon gonadotropin releasing hormone analog (sGnRHa) followed by a resolving dose of 500 μg/g BW. An estimated 21,600 eggs were collected, fertilized (90%), and reared to post-metamorphosed ‘opihi. Overall, this study showed advancement of ‘opihi aquaculture and the first captive reared juvenile ‘opihi ‘alinalina.
The results of studies of honeybee learning suggest that the basic principles of learning are similar in invertebrate and vertebrate species. A surprising result of recent work is that they are capable of forming concepts, a capacity that has been demonstrated in only a few vertebrate species. The question in the research reported here is whether honeybees can solve an oddity problem. In a training technique that relies on the natural tendency of foraging honeybees to seek nectar, the bees were pre-trained one at a time to forage on a multicolored feeding target in a laboratory window. The bee drank to repletion, flew back to the hive to unload, and then returned to the window in 3-4 minutes. After a bee was reliably returning to the multicolored target, training began with sets of three colored feeding targets. The colors used were white, yellow, green, gray, orange, and blue disks (artificial flowers). On each of the 15 training visits, there was a different set of three colors, always with two identical and one different (e.g., yellow, yellow, orange; blue, green, green; orange, white, orange). Choice of the odd stimulus was rewarded with 50% sucrose-solution. Choice of a nonodd stimulus was “punished” with 10% stevia-solution, but the bee was allowed to correct itself and find the sucrose. The bees learned to choose the odd stimulus by the end of training, indicating that they learned the concept of oddity. The bees may use such same/different concepts to make foraging decisions among flower patches.
Previously, we have shown that only two Y chromosome genes, Sry and Eif2s3y, are required to produce a male mouse able to reproduce with assisted reproduction technologies. We have subsequently shown that the function of these genes can be replaced by transgenic overexpression of their homologues encoded on other chromosomes, Sox9 and Eif2s3x, respectively. However, we observed that transgenic males presented with testicular abnormalities of seminiferous epithelium and/or testicular interstitium.
Here, we validated this observation quantitatively using testis cross sections from males with 2, 1 or no Y genes. Because no suitable method existed, we developed a strategy to quantify the area of the testicular interstitium. Stained testis cross-sections were photographed, processed, and analyzed using ImageJ. Macrophages, capillaries and other vascular structures within each cross-section were counted.
The control XY males had significantly larger total and tubular area when compared to transgenics. The apparent increase of interstitium in testis cross-sections from transgenic males resulted from a decreased ratio between the germinal epithelium and interstitial tissue, and not from interstitium overgrowth. Transgenics had more macrophages when compared to XY; males with two Y chromosome genes were the least affected. The number of capillaries and other vasculature structures were elevated in transgenics versus controls.
We demonstrated that mice with limited to no Y gene content have interstitial tissue abnormalities and that these defects vary in different transgenic contexts. Our findings advance the understanding of the male gonad development and the role of Y chromosome genes, and their homologues, in this process.
Bradley Thomas, Yukie Lloyd-Sato, and Diane W. Taylor
Infection with Plasmodium falciparum during pregnancy can result in accumulation of parasites in the placenta, causing placental malaria (PM) with severe consequences for mother and fetus. VAR2CSA, a parasite-derived protein, is expressed on the surface of P. falciparum- infected erythrocytes (IE) and allows the IE to adhere to the placenta. Pregnant women in malaria endemic areas can develop protective antibodies (Ab) that bind VAR2CSA and prevent this adhesion. Many studies have used a small number of malaria-naïve individuals, including pregnant women, to establish cutoffs for seropositivity to VAR2CSA. However, no study has examined large numbers of malaria-naïve pregnant women for Ab that cross-react to VAR2CSA. Based on published and preliminary data, we hypothesized that one-third of malaria-naïve pregnant women would have cross-reactive Ab to VAR2CSA. To test our hypothesis, 213 samples from US pregnant women and 108 samples from healthy, non- pregnant US adults were tested for Ab response to VAR2CSA. Ab levels were measured using a multi-analyte platform (MAP) assay. Less than 5% of our samples showed reactivity to VAR2CSA and its six domains. In our study cohort, high levels of VAR2CSA Ab were observed only in a pooled sample from pregnant women in Cameroon, a malaria-endemic region. 95% of malaria-naive American pregnant women and healthy, non-pregnant US individuals were seronegative for VAR2CSA Abs. This study raises the important question of how to choose appropriate negative controls for a seroprevalence assay to define a scientifically valid cut-off value.
The Hawaiian Band-rumped Storm Petrel (Oceanodramo castro), listed in 2016 as federally Endangered, nests in locations that are difficult to access and spends most of its life at sea. As such, very little is known about movement among islands and the potential for establishing new breeding colonies in managed areas with predator controls. As a first step in assessing connectivity, in this study we evaluated patterns in genetic diversity between populations on two islands known to host breeding populations. Blood or feather samples were collected from twelve birds on Kauai and 6 birds on Hawaii Island. Kauai and Hawaii Island represent the northern and southern extent of the main Hawaiian Islands, and are approximately 300 miles apart. We sequenced nuclear and mitochondrial markers on all individual samples, and performed RADseq on pooled samples from each island. Structuring among populations may be due to high levels of site-fidelity in breeding colonies. Results from this study may be used to inform seabird conservation efforts and provide insights on population connectivity in long- lived taxa.
Hepatitis C virus (HCV) affects the lives of more than 150 million people worldwide. Every year there is an estimated 700,000 deaths due to HCV-related liver disease. This is mainly due to lack of a vaccine and because most acute hepatitis cases are asymptomatic. Due to the high replication rate and high mutation rate in the polymerase gene, HCV has great genetic diversity. Currently there are seven known HCV genotypes and over 60 subtypes. High prevalence of multiple HCV genotypes has been reported circulating in Cameroon, which suggests the possibility of increased genomic recombination among different genotypes. This study was conducted to characterize HCV circulating in Yaoundé, capitol of Cameroon, and to identify potential recombinations within the population. Plasma samples were sequentially collected between June 1, 2016 and July 29, 2016 at Centre Pasteur du Cameroon, a reference laboratory. Viral RNA was extracted from 76 patients suspected of being infected with HCV. PCR was conducted using primers specific for HCV capsid and polymerase (NS5B) genes. Samples positive for HCV RNA were sequenced and analyzed for sequence diversity using bioinformatics tools. Out of the 76 samples tested, 71 were positive for HCV RNA. Of the 71 samples, one was verified with a potential recombination between HCV genotype 4 and genotype 1. These data warrant future studies focusing on i) identifying the site of recombination, and ii) testing the efficacy of genotype-specific HCV treatment on the recombinant virus.
Mayumi Fernandez, Eglė A. Ortega, and Monika A. Ward
Disorders of sex determination (DSDs) are medical conditions in which chromosomal, gonadal, or anatomical sex is atypical. DSDs affect 1 out of 4,500 births and can be caused by mutations in the genes involved in sex determination. Y chromosome-encoded genes are important for male development but their function can be replaced by that of their homologues encoded elsewhere in the genome. We have shown before that males lacking all Y chromosome genes but transgenic for Sox9 and Eif2s3x (XOSox9,Eif2s3x) had poorly developed testes and elevated expression of pro-ovary factors FoxL2, Wnt4, and Rspo1. We hypothesized that partial feminization of adult XOSox9,Eif2s3x testes result from incomplete antagonism between pro-testis and pro-ovary factors during sex determination, which in mice occurs between 10.5 and 12.5 days post coitum (dpc). We generated timed pregnancies, obtained 12.5 dpc fetuses, and isolated genital ridges from XOSox9,Eif2s3x and control XX/XY mice. The size and shape of genital ridges from XOSox9,Eif2s3x males, quantified as length/width ratio, varied from that of XX and XY. The development of testis cord and coelomic artery was also altered in gonads from the transgenic males. Finally, the levels of FoxL2, Wnt4, and Rspo1 transcripts, quantified using qRT-PCR, were in between those observed in XX and XY genital ridges. Together, these data support that the first steps of testis formation during sex determination are impaired in XOSox9,Eif2s3x males. These findings add to the understanding of how the Y chromosome encoded genes and their homologues encoded elsewhere in the genome help to determine sexual development.
Plant growth is the accumulation of biomass attributed to cell division and cell expansion. In the maize leaf, growth is spatially separated into three distinct growth zones. This spatial separation makes the maize leaf a useful model for understanding growth because changes in the cellular morphology of these growth zones reflects changes in the underlying molecular networks driving growth. We previously showed that the semi-dominant maize mutant, Hairy Sheath Frayed (Hsf1) was caused by hypersignaling of the plant hormone cytokinin (CK) which reduced leaf size. CK typically promotes cell division but can repress growth in certain tissues. Analysis of Hsf1 leaves indicated a decrease in the number of dividing cells associated with increased levels of jasmonic acid (JA), a defense and growth repressive hormone. JA is known to reduce cell division in A. thaliana implying that CK-signaling may restrict maize growth through upregulating the JA pathway. We adapted our maize seed hormone assay to establish the effects of exogenous JA application on maize leaf growth. B73 seeds treated with JA exhibited a significant reduction in leaf size and a decreased leaf elongation rate. JA treatments on Hsf1/+ and WT sib seedlings resulted in a greater reduction in leaf size in WT compared to JA treated Hsf1/+ plants, suggesting saturation of JA perception in Hsf1 mutants. Treatments are being repeated to confirm these results. These data help explain the cause of growth reduction in Hsf1 and set the foundation for further studies of JA-mediated growth changes downstream of CK signaling.
Torbjoern Nielsen, Victor A. Ruthig, Jonathan M. Riel, and Yasuhiro Yamauchi
Previously, we reported that only two Y chromosome genes (Sry and Eif2s3y), in the context of a single X chromosome (XO), are needed to produce a male mouse able to sire offspring using assisted reproductive technologies. Sry initiates testis development while Eif2s3y initiates male germ cell (MGC) proliferation and differentiation. We subsequently demonstrated that functions of Eif2s3y can be substituted by transgenic overexpression of its X-linked homologue, Eif2s3x. Furthermore, we have shown spermatogenesis is similar between males with sex determination driven by endogenous Sry (XY) and by transgenic Sry (XYTdym1Sry). Here, we expanded on the previous data by performing quantitative assessment of prespermatogenesis and the first wave of spermatogenesis in XY and XYTdym1Sry neonates. We also investigated effects of variable doses of endogenous Eif2s3y and Eif2s3x on prespermatogenesis and the first wave by comparing males with variable doses of Eif2s3x/y: XY and XYTdym1Sry (1 copy, Eif2s3y), XXSry (2 copies, Eif2s3x), and XOSry (1 copy, Eif2s3x).
At 3 days postpartum (dpp) and 11 dpp, XY and XYTdym1Sry had similar MGC numbers. XY, XXSry, and XOSry males however, showed differences in testicular cell number at 3 dpp, which became exacerbated by 11 dpp. Our data shows that (1) replacement of endogenous Sry with transgenic Sry does not alter pre-spermatogenesis efficiency; (2) presence of two X chromosomes results in MGC loss; (3) lack of Eif2s3y does not negatively affect pre- spermatogenesis. These findings are important for the understanding of the roles of the sex chromosomes and Y chromosome genes in MGC development.
The Effect of an Acute Food Shortage on Human Population Dynamics in a Subsistence Setting
Joshua-Michael Tomiyama, Daisuke Takagi, and Michael Kantar
World population is projected to increase to nearly 9 billion by 2050, this estimate has increased concerns related to food security. Specifically, asking how food production will keep pace with population increase. This is a restatement of a classic problem in demography that was first popularized by Thomas Malthus in the 18th century, which stated that population growth is exponential while food production is linear. The Malthusian model forecasts of catastrophic famine due to exponential population growth. Though the mechanisms of famine are understood, little is known what constitutes a catastrophic famine and the time required to recover from such a famine. Based on Malthusian theory, we propose a mathematical model based on system of equations that predicts food availability and human population in an isolated preindustrial village. After exploring many parameter sets the final model includes three parameters that describe the system. These parameters are maximum calorie production, food production resilience, and minimum calorie requirement per person. Thus this model can be a powerful for quantifying future catastrophic famine events and predicting the outcome over many seasons. Results of the model shows populations to generally be more resilient to famine than Malthusian theory would suggest.
Even-fixation of tissues is crucial for histological analyses. Immersion fixation is a common procedure appropriate for small samples, but when fixing high-lipid containing tissues, such as the whole brain, a challenge arises in which fixative does not penetrate all areas of the specimen at the same rate. This causes the trouble of immunohistochemistry, nerve-tracing, etc. Fixation carried out by the cardiac perfusion of crosslinking paraformaldehyde (PFA) addresses this issue. Here, we developed a rapid perfusion technique for the fixation of Mexican tetra cavefish, Astyanax mexicanus, whose body sizes are < 3cm. We also show neural tracing application and visualization of the central projection of the mechanosensory superficial neuromasts (SN). Since blind cavefish increase their SN 3 times more than their eyed-surface dwelling conspecies, we are interested in the sensory integration at the central nervous system level. In this protocol, to inhibit clot formation in the vascular system, we first placed the tip of a 27G needle into the heart ventricle and perfused the deeply anesthetized fish with 20 mL of ice-cold 10U/mL heparin in phosphate buffered saline (PBS). Immediately after injection, we cut the heart atrium using micro-dissection scissors to drain the blood. A 3- way valve switched the perfusion to 50 mL of ice-cold 4% PFA in PBS. The process of fixation was monitored by the presence of involuntary muscle movement and was continued 10 minutes after muscle movement was first observed. We are now preparing cryostat sections of the prepared-brains and discussing the nerve-tracing results.
Submarine groundwater discharge(SGD) results in release of substantial volumes of higher nutrient, lowered salinity, and variable pH waters into coastal settings of oceanic islands via subterranean aquifers. Where riverine inputs are negligible, SGD may be the dominant source of nutrients to coastal ecosystems. Further, SGD flux can be highly variable among sites. While persistent algal blooms have been linked to SGD tainted wastewater nutrients, a clear gap in our understanding is the influence of SGD on native algae in benthic communities, the physiological trade-offs for natives algae and changes in community species composition. Thus, I hypothesize that SGD influences the physiology and ecology of marine plants. Second, I hypothesize that SGD conditions influence benthic species composition. Correlations between benthic cover and SGD characteristics can be complimented by measurements of algal physiology across a gradient of SGD influence. Measurements of photosynthesis, tissue δ15N, tissue %N, and internal solute potential are used to asses an integrated algal physiological response to SGD conditions. Determining how these plants respond physiologically to different SGD characteristics in concordance with describing changes in benthic cover across SGD conditions will test this relationship between SGD characteristics, benthic species composition, and algal physiology. Determining how the characteristics of SGD influence the benthic community may explain how, in some cases, SGD influences coastal communities to experience a phase shift from coral to algal dominance.
Mariah Opalek, Shayle Matsuda, Raphael Ritson-Williams, and Ross Cunning
Increased occurrences of coral bleaching have devastated reef ecosystems worldwide. However, response to stress isn’t the only factor to consider when assessing long term coral health. The ability to grow can determine whether a species thrives or is out competed. Montipora capitata is a common coral species found in Kane‘ohe Bay, O‘ahu, Hawaiʻi. This species associates with Symbiodinium, single-celled dinoflagellates, in clade C and/or D, which provide nutrients to the host by the process of photosynthesis. Different types of Symbiodinium have been observed playing different roles in the holobiont’s response to stress (clade C, less tolerant; clade D, more tolerant), and differences have also been observed in growth patterns (clade C < clade D). We hypothesize that clade C dominant Montipora capitata will have higher growth rates than colonies dominated by clade D at the same depth; however, growth will differ across environmental gradients (or depths) due to differences in irradiance. Montipora capitata fragments will be collected in Kane‘ohe Bay from tagged parent colonies associating with clade C (n=120) and clade D (n=120), and placed into different lighting treatments: 100%, and reductions to 75%, 25% and 5%. Tissue samples for DNA extraction and qPCR will be collected to identify symbiont types: at the beginning of the experiment and after three months in light treatment. Growth will be measured by buoyant weight initially and every four weeks. Understanding how different Symbiodinium impact coral growth will broaden our understanding of the dynamic role symbionts and environment play in coral health.
Daniel Arencibia, Luis Espinoza, Lane Morrow, and Rebecca Katz
Submarine groundwater discharge (SGD) has been known to be a source of inorganic nutrient loading to coastal environments. Studies have shown that SGD seeps occur in Maunalua Bay, O‘ahu, Hawai‘i. Four distinct biogeochemical zones (spring, transition, diffuse, and ambient reef) have been described at Black Point and occur as a result of SGD input. The purpose of this study was to observe differences in the composition of benthic macroalgae in zones because data addressing the impacts of anthropogenic nutrient loading by SGD on algal diversity is lacking. Benthic surveys were carried out in a grid formation (n=116) in order to characterize the biodiversity and relative abundance of macroalgae within each zone. We hypothesized that zones with higher SGD influence would have a higher relative abundance of Bryopsis pennata, an opportunistic alga with a high tolerance to freshwater, and consequently a lower species richness. Our data showed a decreasing average relative abundance of B. pennata in each zone, but results were insignificant, possibly due to the clumped distribution of B. pennata. The biodiversity, calculated using Simpson’s Index of Diversity, for the spring, transition, diffuse, and ambient reef zones were 0.2519, 0.3538, 0.2378, 0.3764 respectively, however, statistical analyses showed no significant difference in biodiversity between zones. Further studies should look into the effects of wave action and other parameters affecting biodiversity in order to understand the complex ecology that occurs as a result of SGD and other interactive environmental variables
9:00 AM Session VI Chaired by Dr. Marguerite Butler
As the field of phylogenetics begins to convert more wholly to a field of phylogenomics, ever increasing amounts of data can be used to test phylogenetic hypotheses. Frequently, reduced representation genomic sequencing is used to reassess phylogenetic conclusions elucidated from limited numbers of mitochondrial and nuclear loci that revealed intriguing, but often conflicting results. In this study, I revisited molecular phylogenetic work which clarified some taxonomic relationships within spiderhunters, but also questioned monophyly of this distinctive genus of sunbirds (AVES: Nectariniidae; Arachnothera). DNA sequence data in this investigation were produced by target-capture sequencing of ultraconserved elements (UCEs) to infer the evolutionary history of 11 species of Arachnothera and six outgroups, including the Purple-naped Sunbird (Hypogramma hypogrammicum), which previous work suggested might lie within Arachnothera. Although we recovered many different gene tree topologies, concatenated and coalescent methods of analysis converged on a species phylogeny with strong support for monophyly of Arachnothera, with Hypogramma as its sister taxon. This talk will focus on the presence of phylogenetically uninformative loci in the UCE dataset, how those loci may impact results, and how consistency across analyses confers confidence that gene tree conflict has been resolved in this enigmatic genus.
The family Pleuronectidae is the group of righteye flounders with 5 subfamilies, 23 genera and 61 extant species, which are common representatives of marine benthic fauna in the northern Atlantic and Pacific. The most recent classification of the family is based on morphological synapomorphies defined after a comprehensive comparison of all pleuronectid taxa. However, several molecular studies have shown that many of these characters might represent a homoplasy and provide a misleading evolutionary hypothesis. In the current study, we propose the complete taxonomic reassessment of the family Pleuronectidae based on its molecular phylogeny. The phylogenetic trees were reconstructed from four nuclear and three mitochondrial loci, using the Bayesian approach. Additionally, we estimated divergence times on the pleuronectid phylogeny based on seven fossil calibrations, which age and phylogenetic position were thoroughly justified. All gene trees and the final species tree revealed a consistent pattern of pleuronectid relationships, which does not correspond with their present classification. The phylogeny included several major monophyletic groups, which we used to define five new subfamilies within the family: Atheresthinae, Pleuronichthyinae, Microstominae, Hippoglossinae and Pleuronectinae. For each subfamily, we provide a description of species composition and reassess the previous statements for morphological synapomorphies. The current study contributes to our better understanding of evolutionary relationships and systematics of fishes.
Squirrelfishes (Neoniphon: Holocentridae) are nocturnal inhabitants of coral reefs, easily identifiable by their red coloration and relatively large eyes. Phylogeographic analysis of the Blood-spot Squirrelfish (Neoniphon sammara) was conducted to elucidate the evolutionary history of this widespread Indo-Pacific fish. We sequenced mtDNA Cytb for 314 specimens from 18 locations across the Red Sea, Indian Ocean and Pacific Ocean. The mtDNA results reveal highly divergent groups (sequence divergence d = 0.06) separated predominantly by the sporadic barrier between the Indian and Pacific oceans. However, mixed populations occurred at the East Indian Ocean location of Cocos and West Pacific locations of Palau and Palmyra, and only Indian Ocean haplotypes were recovered from Fiji. These results indicate Pliocene isolation (approximately 3 million years ago) across the Indo-Pacific Barrier followed by cryptic speciation and subsequent spread of the Indian Ocean form across the West Pacific. These findings support the hypothesis that isolation at the Indo-Pacific barrier is a primary source of reef fish biodiversity.
Evolving animals shift their sensory systems to acquire environmental information and express adaptive behaviors. Some animals further increase their sensory system to gain better information. However, the evolutionary mechanisms by which these altered sensory systems integrate into the brain remain largely unknown. A unique model for understanding such intricate and dynamic relationship is Astyanax mexicanus, a fish with eyed river-dwelling populations (surface fish) and eyeless populations that live in caves (cavefish). In the absence of light, some cave populations have evolved an enhanced Vibration Attraction Behavior (VAB) that allows them to swim towards vibrating prey. VAB is regulated by mechanosensory cells of the Lateral Line, specifically a group of superficial neuromasts (SNs) clustered at the eye orbit of cavefish. Since SNs are scattered across the skin surface but only the ones at the eye orbit are associated with VAB, we sought to quantify the distinct sensing properties of neuromasts at different locations on the body. Here, we present a novel technique by which we record with millisecond resolution the SNs movements and orientations using fluorescein-labeled microsperes. The phase-locked movement of SNs suggests that SNs could signal to the brain at an applied frequency. We are actively testing whether this movevemnt of SNs differs by their cranial position or by cave population.
Stomatopods, commonly known as mantis shrimp, have one of the most complex visual systems of any living species. Adults have a complex eye subdivided into three morphologically discrete regions with more photoreceptor types than any other animal described. Adults are able to see a wide spectrum of visible, ultraviolet, and polarized light. There have been minimal studies on the larval visual system and the metamorphosis from the larval stage to the adult.
The larval eye is a much simpler version of the adult eye, lacking the photoreceptor and visual pigment diversity of the adult counterparts and instead show similarity to any other pelagic crustacean larvae. Upon metamorphosis an entirely new set of optics emerges adjacent to the larval retina, so during a period of time in the larval stage an individual possesses two retinas in a single eye. While it is common for crustacean eyes to undergo metamorphose to the adult state, the stomatopod presents a unique method of having the adult retina emerge separate from the initial structure. The double retina persists for a period of a few hours to several days depending on species, and then is eventually pushed aside, disintegrates, and is reabsorbed. Aside from morphological description, very little is still understood about stomatopod eye development. A better understanding of stomatopod visual ecology will serve to better understand stomatopod eye evolution and how such a complex visual system was able to arise. The proposed focus of my Ph.D. research will be on the understanding this development through a combination of techniques.
Teleost fishes exhibit a dynamic range of sex determining systems and reproductive strategies. This diversity has been extensively explored in the literature, however, the vast majority of studies have focused on gonochoristic fishes (i.e. those with separate sexes). The precise mechanisms for sexual differentiation and maintenance remains poorly understood in hermaphroditic species. The aim of this research project is to identify the distributional pattern of gonial cells (i.e. oogonia and spermatogonia) in the non-partitioned ovotestis of the Hawaiian endemic hermaphroditic goby, Eviota epiphanes. In order to accomplish this goal, we propose to use immunohistochemical (IHC) techniques to identify proliferating cells expressing the vasa gene. This highly conserved gene is directly implicated in sexual determination and differentiation in many vertebrate taxa. Previous studies have shown that the vasa gene is expressed in the cytoplasm of both gonial cells and primordial germ cells (PGCs). We hypothesize that the number of appropriate gonial cells may increase through cell division during transition of sexual function. Alternatively, gonial cells may re-differentiate (i.e. oogonia become spermatogonia and spermatogonia become oogonia), and/or PGCs may be maintained in the ovotestis of adult hermaphroditic fishes and undergo differentiation during sexual transition. The results of this study will provide us with a better understanding of how sexual differentiation, specifically the generation of new and different gametes, is regulated in hermaphroditic fishes.
Kristen Harmon, Melissa Price, Yinphan Tsang, and Ayron Strauch
The Hawaiian stilt (Himantopus mexicanus knudseni) inhabits wetlands across the Hawaiian Islands. Nest initiation of waterbirds is known to be correlated with water depths, which are influenced by precipitation events. In the Hawaiian Islands rainfall varies seasonally and temporally, and in recent years sea level rise has increased the elevation of groundwater tables, contributing to increases in flooding events during heavy rainfall, particularly in wetland environments. The island of O‘ahu experiences heavy rainfall events on its windward side during the months of March and April, during which Hawaiian stilts begin to breed. Timing of nest initiation may have a great impact on nesting success, particularly in wetlands that experience frequent flooding early in the breeding season. I am proposing to utilize observational surveys and camera traps to determine nesting success of Hawaiian Stilts in wetland habitats on the windward and leeward side of O‘ahu. I will use rainfall and water depth data to determine the relationship between rainfall and (1) pond water depths; (2) time of nest initiation; (3) nesting effort; and (4) nest failures. It is expected that high precipitation events will be positively correlated with nest failures in all wetlands, with flooding contributing more to nest failures in windward wetlands than leeward wetlands. The results of our study may be used to inform decisions for managing hydrological conditions of Hawaiian waterbird habitat given future climate predictions.
Sexual size dimorphism (SSD) typically exhibits a response in which the body size of each sex changes based on changes in the environmental conditions, individual fitness, fishing pressure or genetic variation. The most commonly found pattern is that the magnitude of SSD will increase with larger body sizes when males are the larger sex and decrease with increased body size when females are the larger. Age, growth and SSD of the Ehu or ruby snapper (Etelis carbunculus) were investigated using size-at-age data derived from otolith collections
of fishery dependent and fisheries independently caught fish within the Hawaiian Archipelago (n = 217). Size-at-age relationships and longevity data were estimated using transverse sections of saggital otoliths and radiocarbon analysis of extracted otolith core material using accelerated mass spectrometry, respectively. Otolith sections yielded age estimated from 1-24 years, for 19.1 - 59.6 cm Fork Length (n = 197). Longevity estimated validated the traditional ages estimates to 35 years for 20.6 - 60.3 cm Fork Length sizes (n = 20). E. carbunculus show highly asymptotic size-at-age relationships, with most growth achieved within the first 8 years. The maximum age estimated from sectioned otoliths were 18 years (males) and 24 years (females). The longevity estimated from radiocarbon analysis were 15 years (male) and 35 years (female). Results indicate that a differential growth characteristic is evident between sexes, with females increasing size at a faster rate than males, and growing to a larger mean size-at-age than males.
10:45 AM Session VII Chaired by Dr. Floyd Reed
As Hawai’i and other states move toward locally integrated management of coastal resources, a central challenge is to match the spatial scale of management with the life history of species that sustain local fisheries. The purpose of this research is to track reef fishes from the site where they are produced as larvae to the location where they settle on the reef, to provide a direct measurement of population connectivity around O’ahu and adjacent islands. Based on species of concern identified by community members and state agencies, we selected five species for efforts to link spawning grounds to adult habitat: Weke‘ā (Squarespot Goatfish, Mulloidichthys flavolineatus), Manini (Convict Tang, Acanthurus triostegus), Kole (Goldring Surgeonfish, Ctenochaetus strigosus), Ama ama (Mullet, Mugil cephalus), and Omilu (Bluefin Trevally, Caranx melampygus). Specimens of young-of-year and adults will be sampled with fin clips (non-lethally where possible) at 12-18 locations around O’ahu, and single locations in adjacent islands Kaua’i, Ni ihau, and Maui. Kinship will be established with conventional population genetics, parentage analysis, and clustering analysis, based on genomic surveys of individuals with single nucleotide polymorphisms. Our labs at HIMB are at the forefront of analyzing these large data sets using advanced computational techniques. Previous research has demonstrated that some reefs areas are primary producers of fish larvae, and other areas are net receivers of these new recruits. We seek to extend this finding to establish broad patterns of connectivity around O’ahu and neighboring islands.
Rachel Dacks, Kirsten Oleson, and Staci Lewis
In 2015, Palau enacted the Palau National Marine Sanctuary (PNMS) Act to protect 500,000km2 of ocean, representing 80% of its exclusive economic zone (EEZ). The Act also states that a small domestic pelagic fishery will be developed to fish in the 20% of the EEZ that remains open. The economic impacts of the PNMS largely depend on impacts within fisheries and tourism. However, gaps exist regarding key characteristics of these sectors. Our project seeks to better understand the structure of nearshore and offshore fisheries in Palau as well as understand local and tourist perceptions of the PNMS and their demands for reef and pelagic fishes. We conducted a desk study to synthesize available literature and data on fisheries and tourism in Palau. We also carried out interviews with managers of fishing companies, restaurants, and supermarkets to map the flow of fish and invertebrates through Palau’s economy. Finally, we piloted a choice experiment with tourists visiting Palau. We found that a variety of local and imported seafood is available for sale in Palau, though many restaurants noted an unpredictable supply of local reef and pelagic fishes. Several seafood buyers commented on the impacts of the boom in Chinese tourists which peaked in 2015. Our tourist survey data suggests that tourists of different ethnicities have different preferences and willingness to pay for seafood. Our results can help guide the development of the domesticpelagic fishery associated with the PNMS and provide lessons learned to other countries with large-scale marine protected areas.
The recent 2016 IUCN Congress highlighted the inextricable linkages between culture and nature, and the threats that indigenous peoples face in a changing world. Climate change is a major threat to us all, and is already affecting species extinctions and human social systems. However, there is a lack of research that analyzes how indigenous biocultural systems will be affected by continued climate change; this gap is particularly concerning since indigenous peoples manage 80% of the world’s biodiversity. In this project, we integrated cultural context (e.g. harvesting practices) with projected future species ranges, and developed collaborative management strategies to strengthen biocultural resilience to climate change. For this case study, we selected two New Zealand native species of high cultural value to the indigenous Maori people: kuta (Eleocharis sphacelata, Cyperaceae) and kūmarahou (Pomaderris kumeraho, Rhamnaceae) are used for weaving and medicinal purposes, respectively. Future suitability maps for each species were generated by running species distribution models for 50 and 70 years into the future under conditions of low and high greenhouse gas emissions. Suitability maps were then interpreted by adding demographic and cultural information. Our results show a contrasting pattern: the range of kuta shifts away from where it is most culturally important, and the range of kūmarahou expands to include regions where the plant has high cultural use but cannot currently grow. This project serves as a model to improve future biocultural assessments that predict and mitigate the effects of climate change on resources and cultures across the planet.
Many consumers of seafood choose to buy products based on sustainable and environmental practices. Historically, both commercial and recreational fishing has focused on species at higher trophic levels, and as stocks of more desirable species become depleted, less desirable species from lower trophic levels have been progressively targeted by commercial fishing. The decline of more desirable and expensive species, and the increased abundance of less expensive species creates an economic incentive for seafood substitutions: less expensive species are mislabeled for ones that have a higher cost. Mislabeling is illegal, but also misleads the public about the true abundance of individual species of fish and shellfish. Although rates of seafood substitutions have been frequently studied in the mainland U.S.A., no data have been collected in Hawaii. Given Hawaii’s location in the middle of the Pacific Ocean, seafood is abundantly consumed making it less of a target for mislabeling. In the present study, we use molecular genetic analyses to investigate rates and patterns of seafood substitutions in restaurants and grocery stores in Hawaii for comparison to the mainland USA.
1:15 PM Session VIII Chaired by Dr. Peter Marko
Cardiac fibrosis is the primary repair response to injury, caused by excessive deposition of extracellular matrix (ECM) produced by fibroblasts. Despite its clinical and pathophysiological significance, no interventions currently exist to directly treat or reverse cardiac fibrosis. Recent studies have focused on cardiac fibroblasts as a potential therapeutic target for heart disease. However, these studies lacked the ability to target fibroblasts and therefore, have not comprehensively examined the effect that altering fibroblast dynamics may have on functional cardiac tissue. Fibroblasts play an essential role in normal heart function and are a key component of cardiac remodeling via ECM regulation and intercellular communication. Cardiac fibroblasts contribute to angiogenesis by secretion of stimulatory and inhibitory factors, which are stored and released by the ECM as required for regulatory processes. Therefore, we hypothesize that depletion of cardiac fibroblasts will cause vascular changes due to alterations in ECM components. We used a transgenic mouse model which results in a dramatic reduction in the fibroblast lineage of cells. In adult hearts, we observe vascular rarefaction and capillary dilation as early as 7 days after the reduction of fibroblast numbers. Our data suggest marked differences in ECM from fibroblast deficient hearts by decellularization and mass spectrometry. To determine if the ECM microenvironment from fibroblast deficient hearts affects angiogenesis, we will generate ECM coating from lyophilized decellularized matrix and perform tube formation assay using an endothelial cell line. Further evaluation of fibroblast interactions with other cell populations will delineate the mechanism by which fibroblasts reshape the myocardium.
Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by progressive memory decline and loss of cognitive functions. One of the hallmarks of AD is the pathological aggregation of beta amyloid (Aβ) which can switch from helicoidal to β-sheet conformation, promoting its assembly into toxic oligomers. These oligomers have been reported to induce neuronal death and synaptic transmission impairments. However, there is now considerable evidence that in normal healthy brains, soluble oligomeric Aβ functions as a neuromodulator. Recently, we have shown that at low concentrations a naturally produced N-terminal fragment (N-Aβ fragment) is nearly twice as effective as full-length Aβ as a neuromodulator, stimulating receptor-linked increases in Ca2+, enhancing long-term potentiation (LTP) and contextual fear conditioning. In addition, we have shown that N-Aβ fragment reverses the inhibition of synaptic potentiation by full-length Aβ (Aβ42) and protects against Aβ42-induced neurotoxicity. We further identified a hexapeptide core sequence within N-Aβ fragment, YEVHHQ (N-Aβcore), which is found to be equally as effective in Ca2+ signaling. Treatment with N-Aβcore was shown to protect against Aβ42-induced oxidative stress and apoptosis in the neuronal cells. In addition, bilateral injection of the fragment or N-Aβcore into the dorsal hippocampus fully rescued fear memory in the 5X FAD mice. Lastly, stabilization of N-Aβcore and/or D-amino acid-substituted N-Aβcore retained significant activity in enhancing Ca2+ and protecting against Aβ42-induced oxidative stress.
Cardiac fibrosis is a major component of heart disease and a hallmark of decreased cardiac function. Currently, there are no treatments that reduce fibrosis. A better understanding of the enigmatic resident fibroblast is essential for identifying potential signaling pathways for therapeutic intervention. We have found that PDGFRα is uniquely expressed in adventitial and interstitial fibroblasts. When PDGFRα is disrupted we see a rapid and substantial loss in fibroblast numbers. This observation suggests that PDGFRα signaling is essential for fibroblast maintenance and that fibroblasts undergo rapid turnover. Our objective is to determine the mechanism of this loss and what phenotypes result, both at baseline and after injury.
We have found that PDGFRα signaling, specifically through the PI3K signaling pathway, is essential for fibroblast maintenance and that fibroblasts undergo apoptosis and phagocytosis- mediated clearance. While PDGFRα signaling maintains a survival signal in resting fibroblasts, we have found that PDGFRα is required for fibroblast proliferation after injury. In addition, PDGFRα deficient fibroblasts have reduced extracellular matrix as determined by qPCR and Trichrome staining. Activated fibroblasts from PDGFRα haploinsufficient hearts are more sensitive to inflammatory mediator-induced cell death when compared to control activated fibroblasts. Interestingly, resting fibroblasts from PDGFRα haploinsufficient hearts, both before and after injury, did not have an increased sensitivity to TNFα and INFγ. Our studies will delineate the role of PDGFRα signaling in the fibroblast, especially as it relates to the relationship between fibroblasts and inflammatory cells during tissue homeostasis and after injury.
Autism Spectrum Disorder (ASD) is a pervasive, multifactorial neurodevelopmental disorder diagnosed according to three core behavioral paradigms: communication, social behaviors, and motor stereotypies. Mutations in Shank genes accounts for ~1% of clinical ASD cases with Shank3 being the most common gene variant. In addition to maintaining synapses and facilitating dendritic maturation, Shank genes encode scaffolding proteins that build core complexes in the postsynaptic densities of glutamatergic synapses. Adult mice with a deletion of the PDZ domain of Shank3 (Shank3B KO) were previously shown to display ASD-like behavioral phenotype with reported self-injurious repetitive grooming and aberrant social interactions. Our goal was to extensively characterize juvenile Shank3B KO mice through an ASD-relevant behavioral assay battery carried out on key developmental days, and to assess micro-behaviors exhibited within some assays. We demonstrate that ASD-related behaviors, atypical reciprocal social interaction and indiscriminate repetitive grooming are apparent in juvenile stages of development of Shank3B KO mice. Our findings underscore the importance of utilizing Shank mutant models to understand the impact of this gene in ASD etiology. We hope to utilize our results for a comparison in future studies focusing on etiological gene- environment interactions in ASD.
2:30 PM Session IX Chaired by Dr. Megan Porter
Stomatopods possess one of the most intricate visual systems in nature. Their stalked eyes move independently and have multiple spectral and polarization channels, with some species possessing up to 16 spectrally unique photoreceptors expressing 33 opsin proteins. Amazingly the complex retina responsible for these abilities forms over a short period during the last phase of larval development. Growth of the adult retina is accompanied by a gradual degeneration of the larval retina. Very little is known about visual systems in larval or embryonic stomatopods despite the fact that retinas begin to form early in embryonic development. Using transcriptomic analyses, we aim to identify the opsin proteins expressed at embryonic, larval, and adult developmental stages of Pullosquilla thomassini and use this information to describe how the stomatopod sensory system develops. Transcriptomes of retinal tissue from four embryonic stages, a larval stage, and an adult have been assembled using trinity. Preliminary data suggests that adult P. thomassini possess ten middle- wavelength sensitive and six long-wavelength sensitive opsins while larval and embryonic stages express four middle-wavelength sensitive and four long-wavelength sensitive opsins. Expression levels for embryonic, larval, and adult opsins have been compared to create a more detailed picture of the development of the early stomatopod eye and the subsequent transition to the more complex adult eye. We have also found evidence for the expression of other phototransduction genes including Gq alpha, TRP channels, and arrestin proteins. With this information, we can produce a complete picture of the visual signaling cascade.
Few stomatopod species have been well-studied in the Hawaiian Islands; efforts to capture these animals are often made difficult due to the cryptic nature of the adults. While larval stomatopods are fairly ubiquitous in the plankton and can be easily captured, species identification is much more of a challenge. The telson features of the adults are one of the primary means of taxon identification, however, larval stomatopods require a different approach due to their tiny, often undeveloped features, and transparent bodies. DNA barcoding offers a way to identify larval stomatopods to the nearest genera or species, but only if adults have been previously cataloged. Based on current sequences found on ncbi, of stomatopod mitochondrial COI regions, at least three potentially new species of stomatopods have been collected in Hawaii. More work is needed to find adults for morphological comparison to completely identify these new species.
Hawaiʻi’s coral reefs provide several ecosystem services including shoreline protection, habitat for reef organisms, social and cultural value, and tourism revenue. The 2014/2015 mass coral bleaching event resulted in high rates of coral mortality throughout Hawaiʻi. A bleaching event can lead to a shift in the coral reef ecosystem from a coral-dominated state to an algal- dominated state. Coral reef decline can be permanent or temporary, depending on its resilience. Coral reef resilience has three components, including the ability of coral to be replenished after a significant mortality event. This study critically analyzed the ability of potential management actions to promote recovery of Hawaiʻi’s corals following the recent bleaching event. We critically analyzed over 100 scientific articles by categorizing them into weighted categories for each of the 12 potential management actions. We calculated a summed ranking score, which allowed us to prioritize the management actions considering both the quality of evidence and the amount of evidence (or number of papers) available. The management actions with the highest ranking scores included ‘establishing herbivore fishery management areas’, ‘establishing parrotfish size limits,’ and ‘establishing a network of permanent, no-take Marine Protected Areas (MPAs).’ We will present this novel method for analyzing the effectiveness of management actions to promote recovery from climatic events and discuss how it could inform the rule-making process to implement these actions in Hawaiʻi.
Herbivory plays an important role in fostering the resilience of reef-building corals by reducing algal cover and providing space for corals to settle and grow. On Hawaiian coral reefs, sea urchins appear to play a crucial role in mediating algal cover on reef substrates. To further study herbivory’s role in enhancing coral resilience, Dr. Mark Hixon and his lab are conducting a pilot study using artificial coral heads at Hanauma Bay and Waikiki as part of the Coral Resilience Module Experiment (CReME). Six modules (1 m3 each) were constructed at both locations in which three modules have holes completely through the structure and three do not have holes. For the present study, we tested two hypotheses: 1.) modules with holes will have greater urchin abundance and lower macroalgal percent cover due to increased refuge from predation and 2.) Hanauma Bay will have greater recruitment of urchins than Waikiki because settlement cues from conspecifics are greater than at Waikiki due to high local urchin abundance. At present, Hanauma Bay modules with holes have higher densities of urchins and lower macroalgal cover than modules without holes. Because Waikiki had no recruitment of urchins, both module types currently have high algal cover. Although the modules are still undergoing successional changes to the benthic community, this study suggests that a combination of appropriate habitat and sufficient cues from conspecifics for urchins to settle are likely important factors in determining algal cover on Hawaiian coral reefs.
4:00-5:00 PM Keynote Lecture