The relation between feeding and reproduction in Anasterias minuta (Asteroidea: Forcipulata)

Abstract

Anasterias minuta is an oral-brooding sea star and one of the main predators of intertidal benthos in Patagonia, Argentina. The aims of this study were to: (1) assess the temporal pattern of feeding and brooding, (2) evaluate the effect of body size, tidal height and temperature on feeding and brooding, (3) evaluate temporary changes in digestive and sexual organs and (4) investigate the relationships between the predatory and brooding activities. Females do not feed during the brooding period. Spawning proceeded during March. The brooding period was from March to November, with a maximum in May. The population feeding rate varied seasonally, with a maximum in December and a minimum in May. The feeding rate was positively related to water temperature and sea star size; but not with tidal height. An annual cycle exists for pyloric caeca weight in both sexes; lowest values were found during winter, due to brooding female starvation, and a possible decrease in feeding rate of non-brooding females and males. No inverse relationship was found between the pyloric caeca and gonad weights in females, but a lag of 1 month was observed in males, being the maximal pyloric caeca development before the maximum gonad weight, suggesting nutrient translocation.

Keywords:

• Argentina
• brooding
• feeding
• gonad cycle
• Patagonia
• starvation

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Acknowledgements

The authors would like to thank Silvina Rosales, Paula Stoyanoff, Marcelo Sosa, Matias Tourné, Nestor Acosta and Javier Tolosano for their kind assistance in the fieldwork. We are also indebted to Alicia Boraso de Zaixso, John M. Lawrence, John S. Pearse, Howard Feder and one anonymous referee for their useful comments and for editing the English language text.

Notes

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark