Natural Diet of the Common Cuttlefish, Sepia officinalis (Linnaeus, 1758) off Lagos Coast, Nigeria

Abstract. The common cuttlefish, Sepia officinalis is one of the economically important species in the Class Cephalopoda. The study aimed to determine the natural diet of S. officinalis collected off Lagos coast, Nigeria. A total of 1082 samples were caught with the use of bottom trawl nets between 1000 and 1200 hrs over a period of eighteen months (August 2018 to January 2020) from eight stations off Lagos coast. Although the proportion of empty stomach was higher in wet season, the difference was not significant (P>0.05). Frequency of occurrence, numerical and fullness methods were used for analysing the food items. Of the 1,082 specimens examined, 90 (8.32%) were empty stomachs and 992 (91.68%) were found with food. Diet items sighted were grouped into eight major categories; these were fish parts (bones, eyes and scales), crustaceans (amphipods, shrimps and portunid crabs), annelids, filamentous algae, diatoms, sand grains, plant materials and unidentified masses. Crustaceans were the most abundant in large and medium size cuttlefish, while in the small size; fishes were dominant in their stomach contents. Cuttlefish can be regarded as euryphagous; feeding on wide range of organisms. Thus, there is dynamism in the feeding habit from carnivores to omnivorous.