Some observations on the shoaling behaviour of the oil-sardine Sardinella longiceps val.

Abstract

The importance of the knowledge of the behaviour of fish in their natural environment which enables their easier location, the devising of better gear and techniques of capture has long been realized by fishery workers. Studies of that nature already conducted have proved to be of considerable interest and value in the case of various fishes such as the Australian pilchard Sardinops neopilchardus (Blackburn, 1941; Blackburn and Tubb, 1950), the California sardine, Sardinops ccerulea (Anon, 1952), the Japanese sardine, Sardinops melanosticta (Nomura, 1958), the " lemuru", Sardinella allecia (Soerjodinoto, 1958), the Atlantic salmon (Keenleyside, 1958), the tunas, Katsuwonus pelamis (Strasburg and Yuen, 1958), Neothunnus macropterus and Euthynnus yaito (Tester ef al., 1955), the lajang, Decapterus spp. (Soemarto, 1958), the cichlid, Tilapia esculenta, the cat fish, Clarias (Beauchamp, 1958),and the minnow, Phoxinus phoxinus (Jones, 1958). Kesteven (1960) in an exhaustive review has lucidly dealt with almost all aspects of behaviour of fishes. No attempts have hitherto been made towards studies on the shoaling behaviour of fishes of Indian waters. In view of the importance of the fishery of oil-sardine Sardinella longiceps on the south-west coast of India, it was thought desirable to investigate the shoaling behaviour of this species.