HABITAT AND DIET OF EARLY STAGES OF SEPIA OFFICINALIS L. (CEPHALOPODA) IN MORBIHAN BAY, FRANCE

The nursery grounds of Sepia officinalis were identified inthe Gulf of Morbihan, on the Atlantic coast of France, and theirabiotic and biotic features described. From the measurementof the young cuttlefish captured, their growth and developmentcould be followed through a period of five months. Analysisof the stomach contents of the cuttlefish and identificationof the prey consumed gave a measure of their feeding activityand diet. The young animals were concentrated in the two parts(East and West) of Morbihan Bay. These were distinguished bydifferent sediments (sandy-mud in the East and sand with shell-debrisin the West) and by water temperature (higher in the East whichallow a greater growth of the young cuttlefish). These sitesare rich in crustaceans Amphipoda, Brachyura and Macrura whichcompose the diet of young cuttlefish. Fish (Gobiidae and Syngnathidae)appear in the diet from August. The feeding activity of thecuttlefish (given by the repletion quotient) increased fromJune to August reaching about 80% in both parts of the Bay.It decreased to nearly 50% in September and October. (Received 11 February 1997; accepted 25 August 1997)