EVIDENCE FOR COUPLING THE VERTICAL FLUX OF PHYTODETRITUS TO THE DIET AND SEASONAL LIFE-HISTORY OF THE DEEP-SEA ECHINOID ECHINUS-AFFINIS

Data from a temporal sampling programme at 2200 m depth provide eviden ce for a relationship between the diet of the deep-sea echinoid Echinu s affinis and deposition of phytodetritus. Nonlinear regression and '' lack of fit'' analysis resulted in the identification of a number of s easonal fluctuations in the organ and gut content indices of E. affini s. The amount of gut contents were low in winter and high during sprin g and summer months. The proportion of organic matter in the gut conte nts, however, did not show a significant seasonal variation. Planktoni c and benthic material was identified from the gut contents using elec tron microscopy. All these data support the hypothesis that the season al deposition of phytodetritus provides energy for growth and reproduc tion.