Population genetic and phylogeographic insights into the phyllosomal odyssey

Iacchei, Matthew John
Journal Title
Journal ISSN
Volume Title
[Honolulu] : [University of Hawaii at Manoa], [August 2013]
The spatial and temporal scale of genetic connectivity influences ecological and evolutionary processes ranging from metapopulation dynamics to species diversification. The majority of marine species maintain genetic connectivity through pelagic propagules, and propagule duration is hypothesized to limit dispersal potential. This dissertation aims to determine the scales of genetic connectivity when propagule duration is not limiting, and elucidate the factors driving specific patterns. Spiny lobsters (Decapoda; Palinuridae) have one of the longest pelagic durations, with some phyllosoma wandering the wine-dark sea for over a year. To gain insight into this odyssey, I combine mitochondrial DNA sequences and nuclear microsatellites to determine the patterns of genetic connectivity in three Panulirus lobster species. At the broadest geographic extent, I observe significant genetic structure in Panulirus penicillatus (Olivier, 1791) at multiple spatial scales throughout its distribution from the Red Sea to the East Pacific Ocean. Population subdivision corresponds frequently with provincial biogeographic boundaries, and a potential species-level disjunction occurs across the East Pacific Barrier. Notably, certain sites are highly isolated within broader regions of minimal genetic discontinuity. To determine whether regional patterns are generalizable between species, I compare P. penicillatus results from Hawaiʻi to patterns in the Hawaiian endemic, P. marginatus (Quoy & Gaimard, 1825). I document greater genetic structuring for P. marginatus than the broadly distributed P. penicillatus; however, the specific connectivity patterns are not generalizable between species. Finally, I use a seascape genetics approach to understand genetic structuring in P. interruptus (Randall, 1840) from Point Concepcion, California to Bahía Magdalena, Mexico. By combining kinship analyses with traditional F-statistics, I find specific sites within the species distribution are highly differentiated. The magnitude of differentiation is strongly positively related to the proportion of kin at each site, and both are related to the proximity of each site to upwelling regions. In conclusion, even marine species with limitless propagule dispersal potential encounter barriers to gene flow on small spatial and temporal scales. Patterns of genetic connectivity are site and species-specific, and may be driven by larval behavior or site-specific oceanographic processes (i.e., upwelling). This knowledge informs the prudent management of these valuable marine resources.
Ph.D. University of Hawaii at Manoa 2013.
Includes bibliographical references.
Access Rights
Email libraryada-l@lists.hawaii.edu if you need this content in ADA-compliant format.