M.S. - Zoology

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https://hdl.handle.net/10125/2172

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Now showing 1 - 10 of 51
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    The relationship between group size and population abundance in foraging birds and ungulates
    (2023) Rouhbakhsh, Aubtin; Ferguson, Jake M.; Wright, Amber N.; Zoology
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    Phylogenomics of ʻēkaha kū moana: insights for future biodiversity assessments
    (2023) Shizuru, Leah Elizabeth Kamilipua; Toonen, Robert J.; Zoology
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    Mosquito-associated bacterial communities source from diet and environmental substrates
    (2023) Weber, Danya; Medeiros, Matthew C I; Zoology
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    Using single nucleotide polymorphisms to resolve the population structure and origins of deepwater Etelis snappers in the North Pacific Ocean
    (University of Hawaii at Manoa, 2022) Lee, Anne M.; Bowen, Brian R.; Zoology
    Deepwater Etelis snappers economically and culturally support fisheries in Hawai’i and throughout the Indo-Pacific. In Hawai’i, Etelis coruscans (“onaga”) and Etelis carbunculus (“ehu”) are the most abundantly harvested in the Deep 7 Bottomfish Complex, therefore it is important to understand genetic connectivity to make proper management implementations. In addition, understanding their origins will provide further information on how to ensure sustainable stocks within Hawai’i waters. Previous studies have shown that Johnston Atoll is the gateway for marine species to colonize the Hawaiian Archipelago. An alternative route is that marine species can colonize from the west, essentially Japan. To resolve population structure and the origin of the Hawaiian cohorts, we used single nucleotide polymorphisms (SNPs) to assess E. coruscans (N = 59) and E. carbunculus (N = 55), sampled from Japan, Johnston Atoll (nearest habitat south of Hawai’i), the Main Hawaiian Islands (MHI), and the Northwestern Hawaiian Islands (NWHI). Johnston Atoll samples were excluded from E. carbunculus. For both species, Japan was significantly differentiated with pairwise FST values for MHI and NWHI, and there was non-significant FST values between MHI and NWHI. Etelis coruscans showed no significant FST values between Johnston and MHI/NWHI. STRUCTURE plot of Etelis coruscans showed no genetic clustering, indicating larval exchange from both locations, Japan and Johnston Atoll. STRUCTURE plot of E. carbunculus showed clear population distinction between Japan and Hawaiian Islands, therefore we can tentatively suggest larval exchange between Johnston Atoll and Hawaiian population. To explore this idea further, future studies should focus sampling effort on Johnston to accurately make this suggestion. Management implications and strategies are needed to ensure long term sustainability of these populations of deepwater Etelis snappers. The indeterminate origin of the Hawaiian population may indicate that gene genealogies (i.e. phylogeography) are more appropriate than allele frequencies (SNPs) in resolving colonization routes.
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    Insights from foraging behavior on competitive interactions in introduced lizards in Hawai‘i
    (University of Hawaii at Manoa, 2022) Carranza, Jose Angel; Wright, Amber N.; Zoology
    Foraging behaviors have different effects on multiple aspects of an animal’s ecology. The fitness of an animal depends heavily on the body condition of said animal, and foraging has a direct effect on body condition. Foraging behaviors also dictate the types of prey predatory animals hunt, and where they hunt for this prey, both of which can drive competition for food. Exploitation competition could be a mechanism of competition being driven by foraging behaviors. Using focal animal sampling, we compared different aspects of foraging behavior on three species of invasive diurnal lizards in Hawai’i that may be competing for food: Anolis sagrei, Anolis carolinensis, and Phelsuma laticauda. Lizards were housed in single-species populations in experimental enclosures with similar prey and habitat availability. We observed differences in the heights at which Anolis sagrei and Phelsuma laticauda would forage, and Anolis carolinensis overlapped with both species. Anolis sagrei and Anolis carolinensis used the ground to forage, whereas Phelsuma laticauda was rarely seen using the ground to forage and used smooth substrates more than the other two species. Both Anolis species had similar long distances traveled to a prey item, whereas Phelsuma laticauda rarely traveled long distances to attempt to capture prey. There was overlap between all three species in the prey taxa they would hunt, which is supported by other work done on Anolis. Because of overlap in foraging behavior seen among the species, exploitation competition could be occurring and help explain why Anolis carolinensis has declined in abundance on O’ahu since the introduction of the other two species.
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    Life History Differences Along The Fast-slow Continuum In Introduced Lizards In Hawai‘i
    (University of Hawaii at Manoa, 2022) Alascio, Spencer D.; Wright, Amber N.; Zoology
    A species’ life history is the set of traits related to the timing and nature of events related to growth, reproduction, and survival. Life history strategies often occur along a ‘fast’ vs. ‘slow’ continuum, and fast life histories are frequently associated with invasion success. We documented life history traits in introduced brown anole (Anolis sagrei), green anole (Anolis carolinensis) and gold dust day gecko (Phelsuma laticauda) lizards to determine whether species differences along the fast-slow axis can help explain community changes on Oʻahu, Hawaiʻi over time. Single species populations were established in replicate 10m x10m seminatural enclosures and censused weekly for one year to track growth and survival of colonists and their offspring. We fit capture-mark-recapture models and logistic-by-weight growth models to estimate population size, survival rate, and time to sexual maturity. We documented a tradeoff between growth and survival, two key life history traits on the fast slow continuum. Brown anole females reached sexual maturity twice as fast as female green anoles and almost three times as fast as female day geckos, while male brown anoles had the lowest monthly survival probability compared to all other groups. Brown anole population estimates showed rapid population increase and high densities, and day geckos reached similar population abundance to brown anoles by the end of the study. Conversely, green anoles decreased in population size and abundance remained lower than the other species throughout the study. All three species had comparable total biomass estimates over time despite variation in abundance, suggesting an upper limit on lizard biomass set by resource availability in enclosures. The high abundance of brown anoles and day geckos, coupled with the low population abundance of green anoles, despite being on relatively opposite ends of the fast slow continuum, mirrors observed population dynamics on O‘ahu where green anoles have become rarer following the introduction and spread of the other two species. These results suggest that relatively extreme life history strategies may be favored in this environment.
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    The Visual Opsin And Phototransduction Pathway Genes Associated With Eye Reduction And Loss In Bat Flies (Streblidae, Nycteribiidae)
    (University of Hawaii at Manoa, 2021) Atkins, Melissa Leigh; Porter, Megan L.; Zoology
    Evolutionary reduction of visual sensing ability is common in troglobiont species where no light filters into the habitat. Independent of light environments, parasitism is also well-known to be associated with a reduction in eye structures. The combination of these two ecological features is exhibited in the aptly named bat fly, a parasitic arthropod that feeds on bat hosts, many of which are cave-roosting. In line with other parasitic arthropods, bat flies exhibit rudimentary development of their visual system. They are derived from fully visual, free-living ancestors, but the varying degrees of eye reduction observed throughout the clade make them a unique group of species to study. Although both parasitic and troglobitic species are well-known to be associated with a reduction in eye structures, the extent of gene loss and transcription attenuations that are accompanied with eye-loss are not well-studied. In insect compound eyes, visual perception is dependent on the number of ommatidia present and how light is focused onto the underlying receptors. Thus far, studies of bat fly macro-morphology from different species have described eyes containing from 0 to 57 facets. This diverse macro-morphology is thought to reflect microstructural changes associated with low light levels such as rhabdomere rearrangement of photoreceptor cells. In order to investigate changes in the molecular components associated with these anatomical changes, I assembled de novo transcriptomes from eight bat fly species and de novo genomes from seven bat fly species. These 15 samples represent a taxonomically diverse set of species with facet numbers ranging 0 to 12. All assemblies were annotated for opsin genes, which encode proteins that are responsible for light detection. Thus far, our analyses of genomes reveal that a common dipteran rhodopsin, Rh1, is present in all bat fly species, with an additional rhodopsin, Rh6, present in Cyclopodia dubia, though Rh1 was the only opsin to have expression at the transcriptome level. Multi-level analyses using both transcriptomes and genomes allows for confirmation of sequences and a more comprehensive understanding of the RNA transcript expression levels in reduced eyes. This work aims to elucidate the evolutionary trajectories of broader ectoparasite and troglobiont trends in visual system reductions through the absence of rhodopsin paralogs and phototransduction cascade genes.
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    A taxonomic study of the Spionidae (Annelida: Polychaeta) from the Hawaiian Islands and Johnston Atoll with notes on their ecology and biogeographical distribution
    (University of Hawaii at Manoa, 1981) Ward, Linda Ann; Zoology
    Examination of polychaetous annelids collected from the intertidal and subtidal waters of the Hawaiian Islands and Johnston Atoll between 1975 and 1980 has led to the identification of 30 species of Spionidae which are described here. Twenty-four of the 3