Evolutionary and Population Dynamics of Crustaceans in the Gulf of Mexico

Authors

Laura Timm, Florida International UniversityFollow

Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Biology

First Advisor's Name

Heather Bracken-Grissom

First Advisor's Committee Title

Committee Chair

Second Advisor's Name

Jose Eirin-Lopez

Second Advisor's Committee Title

Committee Member

Third Advisor's Name

Mauricio Rodriguez-Lanetty

Third Advisor's Committee Title

Committee Member

Fourth Advisor's Name

Eric von Wettberg

Fourth Advisor's Committee Title

Committee Member

Fifth Advisor's Name

Wensong Wu

Fifth Advisor's Committee Title

Committee Member

Keywords

Crustacea, Decapoda, Evolution, Phylogeny, Population Genetics/Genomics, Farfantepenaeus, Shrimp, Giant Deep-Sea Isopod, Mesopelagic, Gulf of Mexico

Date of Defense

6-7-2018

Abstract

Evolution occurs and can be conceptualized along a spectrum, bounded on one extreme by the relationships between deep lineages – such as phyla, classes, and orders – and on the other by the molecular dynamics of operational taxonomic units within a species, defined as population genetics. The purpose of this dissertation was to better understand the evolutionary and population dynamics of crustaceans within the Gulf of Mexico. In the second chapter of my dissertation, I provide a guide to best phylogenetic practice while reviewing infraordinal relationships within Decapoda, including the promise held by next-generation sequencing (NGS) approaches such as Anchored Hybrid Enrichment. Chapter III is a phylogenetic study of species relationships within the economically important shrimp genus, Farfantepenaeus, targeting three mitochondrial genes and uncovering an intriguing pattern of latitudinal speciation. As the first inclusive molecular phylogeny of the genus, we find support for the newly described species F. isabelae, but a lack of support for the species status of F. notialis. Additionally, our results suggest the existence of two distinct subspecies of F. brasiliensis. Chapter IV investigates the relative impacts of habitat heterogeneity and the presence of a possible glacial refugium in determining population dynamics of the Giant Deep-Sea Isopod, Bathynomus giganteus in the northern Gulf of Mexico. Through hybrid population genetics/genomics analyses and Bayesian testing of population models, we find strong evidence for habitat heterogeneity determining population dynamics for this charismatic deep-sea invertebrate. Chapter V further investigates the role of environment in determining and maintaining genetic diversity and population connectivity, specifically focused on establishing biological baselines with which we can diagnose health and resilience of the Gulf of Mexico. This was accomplished through a comparative NGS population genomics study of three species of mesopelagic crustaceans: Acanthephyra purpurea, Systellaspis debilis, and Robustosergia robusta. While diversity and connectivity differs in each species, the comparative results bespeak the importance of access to the Gulf Loop Current in determining and maintaining population dynamics. Overall, my work significantly contributes to our knowledge of Crustacea at the phylogenetic- and population genetic-level.

Identifier

FIDC006826

ORCID

0000-0002-7285-0261

Recommended Citation

Timm, Laura, "Evolutionary and Population Dynamics of Crustaceans in the Gulf of Mexico" (2018). FIU Electronic Theses and Dissertations. 3807.
https://digitalcommons.fiu.edu/etd/3807