Meeting Abstract

P3.110  Friday, Jan. 6  Low salinity decreases juvenile production in the sea urchin Lytechinus variegatus (Echinodermata:echinoidea) FRITZ, R.M; GEORGE, S.B.*; Georgia Southern University; Georgia Southern University georges@georgiasouthern.edu

Due to current changes in climate and weather patterns, echinoderm larvae may be exposed to prolonged periods of low salinity along the East coast. In a series of experiments, the effects of prolonged exposure to low salinity on Lytechinus variegatus larval mortality, development and the number and size of juveniles produced were analyzed. Prolonged exposure to 25‰ seawater significantly increased larval mortality and prolonged development. Larvae exposed to 25‰ seawater throughout development, and those transferred from 25‰ to 32‰ seawater after 40 days at the lower salinity, failed to metamorphose. Exposure of eight-arm larvae to 28‰ and 25‰ seawater increased the time to metamorphosis to 44 and 49 days after fertilization respectively and significantly decreased the number of juveniles produced (57 and 18 respectively). In comparison, larvae exposed to 32‰ seawater throughout development began to metamorphose 35 days after fertilization. Two hundred and thirty-three juveniles were produced from this latter treatment. Overall, prolonged exposure to low salinity negatively affected Lytechinus variegatus larvae by increasing larval mortality, prolonging development, delaying metamorphosis, and decreasing the number of juveniles produced.