Ashton-Urrego, M. A.. Univerity of Puerto Rico-Mayaguez, NA
Tosteson, C. A.. University of Puerto Rico-Mayaguez, cigua@aol.com
Tosteson, T. R.. University of Puerto Rico-Mayaguez, cigua@aol.com

 
TOXIN PRODUCTION IN RELATION TO ELEVATED TEMPERATURE EXPOSURE IN LABORATORY CULTURED OSTREOPSIS LENTICULARIS
 
The benthic dinoflagellate O. lenticualris has been shown to be the major vector associated with ciguatera in Caribbean finfish on the southwest coast of Puerto Rico. In field experiments conducted with O. lenticularis it has been established that after periods of elevated environmental temperature (30 days, >29.5 C) the harvested dinoflagellates showed significant increases in toxicity, specifically increases in toxicity/cell. Laboratory cultured O. lenticularis exposed to elevated temperatures (30-31 C) during their light cycle for 33 and 54 days showed significant increases in toxicity. O.lenticularis cultured at temperatures of 25-26 C yield lower quantities of extractable toxin, with increased specific toxicity (toxicity/mg toxin). The increase in toxicity for cultures exposed to elevated temperatures resulted from the recovery of more extractable toxin rather than increases in the specific toxicity of the extracted material. The resulting increased toxicity of O.lenticularis may result from the effects of elevated temperatures on their metabolism and/or the microbial symbionts found in association with these microalgal vectors. Preliminary studies demonstrate that the number of Acinetobacter and Pseudomonas/Alteromonas bacteria associated with the dinoflagellate was significantly reduced when exposed to elevated temperatures. SS42 CS24 SS40 Poster
 
Day: Thursday, Feb. 4
Time: Poster
Location: Sweeney Center
 
Code: SS42TH0093S