ABSTRACT
Within the context of a research on sea-urchin cultivation (Paracentrotus lividus), the effect of light on the amount of food ingested and of faeces produced per echinoid per day has been investigated. Three sets of 20 adults were subjected to particular light conditions (constant light, constant darkness or 12 hours of light per day) for 6 days. Measurements were done for each of the 60 investigated echinoids. Calculation of the mean daily feeding and absorption rates for each set of individuals indicates that the highest values were obtained for echinoids at constant darkness and the lowest for echinoids subjected to light/darkness alternation (values for the three sets of individuals are significantly different).
