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Full-Text Articles in Life Sciences

A Comparative Analysis Of Extant Oceanic Shark Species Using Trait-Based Ecology, Elizabeth A. Johnson Aug 2024

A Comparative Analysis Of Extant Oceanic Shark Species Using Trait-Based Ecology, Elizabeth A. Johnson

All HCAS Student Capstones, Theses, and Dissertations

Over the past few decades, scientists have been working together to mitigate human impacts on global shark populations, but deciding which species need the most immediate attention can be difficult. This study uses a newly emerging approach to ecology, trait-based ecology, to identify trends in trait expression with depth and determine which species have the most unique sets of traits. While trait-based ecology has already been applied to numerous fields, a trait-based approach to shark research is still in its infancy. A total of 15 traits across 337 oceanic shark species were examined to identify trends in trait expression and …


Determination Of Atlantic Shortfin Mako Shark (Isurus Oxyrinchus) Population Genetic Structure And Comparison Of Mitogenomic Markers, Marissa Mehlrose Aug 2022

Determination Of Atlantic Shortfin Mako Shark (Isurus Oxyrinchus) Population Genetic Structure And Comparison Of Mitogenomic Markers, Marissa Mehlrose

All HCAS Student Capstones, Theses, and Dissertations

This study provides the first genomics-level, population structure and genetic diversity assessment of the shortfin mako (Isurus oxyrinchus) shark. The assessments were based on mitogenome sequences from makos distributed throughout the Atlantic Ocean, with Pacific mako mitogenomes used as a comparative outgroup. In addition to complete mitogenome-based analyses, I assessed individual mitochondrial coding gene and non-coding (Control Region) sequences for their comparative resolution properties as markers for revealing matrilineal population structure and genetic diversity. Sequencing of 125 makos in the western and eastern Atlantic across northern and southern hemispheres yielded 92 complete mitogenomes (16,698-16,702 bp) and 33 partial …


Genetic Population Dynamics Of The Critically Endangered Scalloped Hammerhead Shark (Sphyrna Lewini) In The Eastern Tropical Pacific Ocean, Sydney P. Harned Aug 2021

Genetic Population Dynamics Of The Critically Endangered Scalloped Hammerhead Shark (Sphyrna Lewini) In The Eastern Tropical Pacific Ocean, Sydney P. Harned

All HCAS Student Capstones, Theses, and Dissertations

The scalloped hammerhead shark, Sphyrna lewini, is a Critically Endangered, migratory species known for its tendency to form large aggregations of mostly adult females, especially in the heavily-fished Eastern Tropical Pacific (ETP) Ocean. This species forms iconic, visually spectacular, seasonal aggregations in the northern Galápagos Islands, and it is hypothesized based on telemetry studies that pregnant females from these aggregations migrate to mainland coastal nurseries for parturition. This study investigated the population genetic dynamics of the scalloped hammerhead across most of its coastal and offshore distribution (Mexico to Ecuador) in the ETP, focusing on young-of-the-year animals sampled from nursery …


A Shark Conservationists Toolbox: Current Dna Methods And Techniques Aiding In The Conservation Of Sharks, Arianna N. Nixon Aug 2020

A Shark Conservationists Toolbox: Current Dna Methods And Techniques Aiding In The Conservation Of Sharks, Arianna N. Nixon

All HCAS Student Capstones, Theses, and Dissertations

Elasmobranchs are important members of their community. Many sharks are important apex predators that help maintain the health of their ecosystem. However, shark populations are globally declining. This is partially due to the fact that sharks are highly targeted for their fins, meat, liver oil, teeth, and skin. However, they are also killed from anthropogenic effects such as habitat destruction and pollution. Most shark species have life history characteristics that also make them more vulnerable to overfishing. Sharks are also difficult to study due to their elusive nature and identification issues. That is why molecular tools are increasingly becoming important …


To Feed Or Not To Feed: Examining The Effects Of Provisioning Tourism On Nurse Sharks In Caye Caulker, Belize, Carlee Jackson Aug 2020

To Feed Or Not To Feed: Examining The Effects Of Provisioning Tourism On Nurse Sharks In Caye Caulker, Belize, Carlee Jackson

All HCAS Student Capstones, Theses, and Dissertations

Wildlife tourism is increasing in popularity around the world, creating the need to understand alterations in animal behavior and spatial distributions that may occur due to associated anthropogenic disturbances. Nurse sharks (Ginglymostoma cirratum, Bonnaterre 1788) are commonly used for wildlife tourism within the Caye Caulker Marine Reserve in Belize. Shark and Ray Village (SRV) is a site within the reserve where nurse sharks are consistently fed by tour/snorkel boats to create an interactive experience with tourists, termed provisioning tourism. Prior to this experiment, no studies had been conducted in SRV to evaluate the impact of provisioning tourism (tourism …