DEAL, K. J.; JOHNSON, K. B.*; Florida Institute of Technology: The Effects of Food Level and Trophic Copper on the Development and Metamorphosis of Lytechinus variegatus Larvae

Pluteus larvae of the sea urchin Lytechinus variegatus were raised on algae contaminated by a range of toxic copper concentrations (free Cu²⁺). The microalga Rhodomonas lens, after being cultured in the presence of 0, 3, 12, 48, 100, 200 and 500 µg l^-1 of toxic copper, was separated from the contaminated growth medium and fed to pluteus larvae. This approach delivers trophically transferred copper, but reduces larval exposure to soluble toxic copper in surrounding water. Growth, survival, and metamorphosis of larvae were measured, but there were no observable morphological or developmental effects and toxic copper does not appear to transfer from phytoplankton to zooplankton via the trophic pathway. Aside from the question of copper effects, starvation elicited plasticity in development (metamorphosis) and larval morphology (arm length). This plasticity is similar to that observed in a number of urchin species when subjected to low food conditions.