Testing cocolitophoro Emiliania huxleyi on an aquaculture‐produced purple sea urchin ( Paracentrotus lividus ) larvae diet

Abstract

The nutritional quality of Paracentrotus lividus larvae's feed plays an important role in their survival and development. The lipid profile of microalgae is largely reflected in the successful development of different metamorphoses. Emiliania huxleyi is the most common cocolitophoro in the oceans and the most important microalgae for calcium carbonate sedimentation on the ocean floor. Despite its biological and geological importance, the application of this microalgae in sea urchin larvae feeding is still unknown. In this work, the performance of E. huxley was evaluated as a P. lividus larvae feeding. Three diets were tested: D1: (Rhodomonas marina), D2 (R. marina, Skeletonema costatum, Emiliania huxleyi) and D3 (E. huxley). Larvae fed with the D2 diet (75.8%) and D3 (74.9%) had a survival at 15 DAH higher than D1 (48.7%). Larvae development was significantly higher in larvae fed with more than one species of algae (D1 and D2), compared with larvae fed only with E. huxley. On day 15 DAH, the number of larvae in the pre-fixation state was much higher in D1 and D2. The analysis of the E. huxley fatty acid profile has a relatively low content of total fatty acids, being, however, rich in DHA (22: 6ω3). The DHA/EPA ratio in these microalgae is significantly higher than the other microalgae used in this work. This research also found that a multiple microalgae species diet promotes optimal development, with the E. huxley species contributing to a high survival rate.