This project used molecular genetic markers (microsatellites) to determine the amount of genetic diversity within populations and whether significant differentiation exists among Florida populations of the long-spined sea urchin, Diadema antillarum. Specifically, this project aimed to (1) compare genetic diversity of D. antillarum from six populations in south Florida ranging from Biscayne Bay, the Florida Keys, and Dry Tortugas, and (2) determine whether two broodstock populations of D. antillarum contain variation indicative of native Florida populations. Together, these questions can address whether broodstock populations contain the genetic variation necessary to meet the Florida Fish and Wildlife Conservation Commission’s (FWC’s) genetic policies for reintroduction throughout south Florida. Global FST among native populations was 0.0004 with a highest pairwise FST of 0.0025 between the Upper Keys and the area west of Key West, showing an overall trend of little natural differentiation between populations. Global FST for all populations inclusive of the broodstock samples was 0.0019 with a highest pairwise FST between a native population and broodstock of 0.0066 between Dry Tortuga and Mote’s broodstock, indicating little differentiation resulting from captive breeding. Average allelic richness and heterozygosity ranged from 22.6–24.4 and 0.937–0.956, respectively, for each population. Two-way ANOVAs comparing genetic diversity between native and broodstock populations showed no statistical difference in allelic richness (F= 3.892, p= 0.0535) or heterozygosity (F=1.43, p=0.237). The computer program STRUCTURE estimated the most likely number of genetic clusters to be k=1, inclusive of broodstock populations, further indicating a lack of differentiation either among native populations or between native and broodstock populations. These data suggest that captive-bred individuals of D. antillarum could be used for reintroduction as part of a plan to re-establish healthy urchin populations throughout the Florida Keys.
Bachelor of Science (B.S.)
College of Sciences
Orlando (Main) Campus
Length of Campus-only Access
Chandler, Luke M., "Genetic Differentiation Among Florida Populations of Diadema antillarum" (2016). Honors in the Major Theses. 44.