Student Research Projects

Opisthobranch Mollusks across the Upper Keys of Florida: Systematics and Development

Student Andrea Rodriguez ‘14
Faculty Mentor(s)
Department Biology
Course Biology 489: Research Methods in the Natural Sciences


Opisthobranch (sea slug) populations in the Florida Keys are threatened by a variety of anthropogenic activities such as habitat destruction and eutrophication. The most recent study assessing biodiversity in 1994 only focused on one group of opisthobranchs (Order Ascoglossa). The purpose of this study is to assess current biodiversity and examine developmental patterns in opisthobranch mollusks from the Florida Keys. Sixteen sites: 8 sites in the Florida Bay and 8 sites in the Atlantic Ocean were sampled. Collections were made in the intertidal zone, shallow water, on patch reefs, under rocks, and within mangrove roots while wading and snorkeling. To consider the possible effects of environmental parameters, habitat type, depth, water temperature, and salinity was recorded for each site at the time of sampling. Living specimens were maintained at Keys Marine Laboratory (KML) in Long Key where specimens were identified and cultured to document embryonic development and determine developmental mode. A total of 76 specimens and 14 species were collected, representing four of the five major opisthobranch orders. Two species can be considered abundant (n > 15). Four species can be considered rare in abundance (n=1). Four species were collected from both coasts of Florida. These data reveal a diverse assemblage of opisthobranchs in the upper Keys. Not all previously recorded species were collected in this study; however 50% of collected species were from undocumented sites. Twenty-one percent of collected species (n = 3) spawned in the laboratory. The size of spawn, size and volume of the egg capsules, and egg diameter were recorded upon deposition. Embryonic development was observed daily through hatching. Mode of development was inferred for embryos not surviving through hatching. Egg diameter ranged from 140-157 µm. Two species, Haminoea antillarum and Phyllaplysia engeli were determined to have Type 3 development. Based on the small number of eggs per mass and large egg diameter, development for the third species, Ercolania fuscata, is hypothesized to be either Type 2-lecithotrophic or Type 3-encapsulated development.


Project took 1st place at VWC's annual 2014 Undergraduate Research Symposium, Division of the Natural Sciences and Mathematics