ECOLOGY OF SEPIOLA-ATLANTICA (MOLLUSCA, CEPHALOPODA) IN THE SHALLOW SUBLITTORAL ZONE

The ecology of the sepiolid Sepiola atlantica in Firemore Bay, Loch Ew e, on the west coast of Scotland was investigated by beam trawling sur veys. Low densities of this species were present in the shallow sublit toral zone of the sandy bay. A size range of 4-21 mm dorsal mantle len gth (DML) was obtained, with no significant differences detected betwe en the mean sizes of males and females. Males reached gonadal maturity slightly earlier and at a slightly smaller size than females. Sepiola atlantica was present in the bay in each of the months in which sampl ing took place suggesting a resident population, the structure of whic h varied considerably. Juveniles were found over a prolonged period of the year but peak recruitment (animals of 4-10 mm DML) was in May and July. Animals <4 mm DML were not caught and no egg masses were found in the trawls. In aquarium conditions, S. atlantica fed on live crusta ceans such as mysids, Crangon crangon and Palaemon serratus, although Corophium volutator, an estuarine crustacean not normally found in the marine sandy bay, was the most accepted food.