Feeding of Pseudechinus magellanicus (Philippi,1857) (Echinodermata. Echinoidea) In the SW Atlantic coast (Argentina).

PENCHASZADEH, P.E., BIGATTI, G., MILOSLAVICH, P.

Ophelia

Año: 2004 vol. 58 p. 91 - 99

ABSTRACT The gut contents of Pseudechinus magellanicus collected from different habitats from Buenos Aires to Usuhaia were analyzed. In mussel beds of the Province of Buenos Aires at 50 m depth, the most important food item was Mytilus edulis platensis spat. In communities without M. edulis the food preferences were Balanus sp., foraminiferans, polychaetes and algae. In beds of the mytilid Aulacomya atra at 5-10m depth, the main food items were Ostrea sp. spat and different algae: Rodophyceae, filamentous algae and Ectocarpus sp. In Usuhaia the sea urchin preyed on ostracods, foraminiferans and algae. MDS analyses showed that the diet of P. magellanicus depends mostly on the kind of substrate in which they inhabit. Our data indicate that P.magellanicus from Argentina is omnivorous, consuming any available food resource: capture drift algae with the aboral tube feet, graze on sessile algae and predate on animals