The influence of density on survival and larval development in the sea urchin Arbacia dufresnii (Echinodermata: Echinoidea)

Introduction: Density is one of the critical factors in echinoderm larvae for aquaculture purposes. Echinoplutei are very sensitive to overcrowding. High culture density can lead problems with bacteria or protozoa, decreasing survival and generating abnormal morphotypes. Objective: To evaluate effect on larval growth sea urchin Arbacia dufresnii. Methods: Two days after fertilization A. dufresnii we kept treatments at 1, 3, 5 10 larvae.ml-1, three replicates each. We recorded morphotypes periodically, as well growth:somatic rod length, total length post oral arms,. applied generalized linear models. Results: Survival dependent density, time replicates, their interactions. Larval depended time, also interaction between variables. The treatment larvae.ml-1 had highest condition. Conclusions: best results larvae.ml-1.