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Full-Text Articles in Life Sciences
Assessment Of Genetic Diversity In Largetooth Sawfish, Pristis Pristis, Populations Over The 20th Century, Ann Fearing
Assessment Of Genetic Diversity In Largetooth Sawfish, Pristis Pristis, Populations Over The 20th Century, Ann Fearing
Master's Theses
The Critically Endangered Largetooth Sawfish, Pristis pristis, experienced global declines in range and abundance over the past century and Australia is now their last stronghold. This research aimed to understand whether these declines have been accompanied by a reduction in levels of genetic diversity. Using P. pristis tissue samples sourced from natural history specimens, three fragments (616-bp, 386-bp, 141-bp) in the mitochondrial DNA (mtDNA) control region were PCR-amplified. At each fragment, significant genetic structure was found in P. pristis overall (ΦST=0.946, N=9; 0.813, N=54; 0.771, N=99). The Indo-West Pacific and Atlantic/Eastern Pacific each harbor genetically distinct lineages of …
Development And Employment Of Environmental Dna Methods For The Detection Of Bull Sharks (Carcharhinus Leucas) In A Freshwater And Estuarine Interface In The Mobile-Tensaw Delta And Mobile Bay, Alabama, Katherine Schweiss
Master's Theses
Species conservation and management is influenced by the quality of monitoring methods employed, especially when targeting elusive, but ecologically significant species, like elasmobranchs. Bull Sharks (Carcharhinus leucas) are highly mobile predators that rely on estuaries and freshwater rivers for maturation, resources, and refuge; their ability to withstand changing environmental conditions may mean they are linking ecosystems through their habitat usage and movements. Rather than setting nets or attaching acoustic monitoring devices, which can be expensive, time-consuming, and invasive, the analysis of environmental DNA (eDNA) for tracing species presence was used to target C. leucasDNA. The present research …
Characterization Of Andrenocortical Tissue Morphology, Histology, And Steroid Synthesis Among Finetooth (Carcharhinus Isodon), Blacktip (Carcharhinus Limbatus), Atlantic Sharpnose (Rhizoprionodon Terraenovae), And Bonnethead (Sphyrna Tiburo) Sharks, Danielle Elizabeth Bailey
Master's Theses
Adrenocortical (interrenal) tissue is composed of steroidogenic cells that produce corticosteroids involved in the stress response and hydromineral balance. Previous research characterizing the elasmobranch interrenal suggests that the number of interrenal bodies that produce the single primary corticosteroid, 1a-hydroxycorticosterone (1a-OHB), varies among species. However, potential species-specific differences in the amount of interrenal tissue and major steroid products produced have been understudied. To address this critical gap in our understanding of elasmobranch biology, this study examined interrenal morphology, cell structure, steroidogenic enzyme distribution (3bHSD), and steroid production in four shark species: Finetooth Carcharhinus isodon, Blacktip Carcharhinus limbatus, Atlantic Sharpnose …
Age, Growth, Reproduction, And Diet Of The Finetooth Shark, Carcharhinus Isodon, In The Northern Gulf Of Mexico, Jeremy Michael Higgs
Age, Growth, Reproduction, And Diet Of The Finetooth Shark, Carcharhinus Isodon, In The Northern Gulf Of Mexico, Jeremy Michael Higgs
Master's Theses
The current study examined life history parameters of the finetooth shark, Carcharhinus isodon, in the northern Gulf of Mexico (nGOM) to provide an accurate description of the species’ reproductive biology, age, growth and diet composition. A total of 1,489 finetooth sharks (830 female; 659 male) were collected from coastal waters of the nGOM between Apalachicola Bay, Florida (29.873° N and 84.514° W) and East Bay, Louisiana (28.959° N and 89.279° W) from June 2006 through October 2013. Peak reproductive development occurred during May/June for both males and females, which was followed by mating and an 11-12 month gestation period. …