Feeding, defaecation and absorbtion efficiency in the sea urchin Parechinus angulosus

Feeding, defaecation and absorption rates were estimated for a controlled laboratory population of Parechinus angulosus. Both feeding and defaecation were power functions of mass. Expressed for an animal of standard size, annual population consumption was estimated as 14% of the annual kelp production at Oudekraal , Cape Peninsula. Absorption efficiency did not vary with size of animal and was shown to be cons iderably higher than the predicted value of Ricklefs (1973).