Growth variations in the Indian oil sardine, Sardinella longiceps Valenciennes

A study of the Variations in the rate of growth of economically valuable fishes forms an important aspect of their biology. In the Indian oil sardine, Sardinella longiceps, this has not received due attention so far, although brief references to growth-variations have been made by some of the previous workers. Homell and Nayudu (1924) stated that growth is tremendous in the first year and negligible subsequently. Devanesan (1943), from a study of the growth rings on the scales, gave the sizes of the different year-classes. Chidambaram (1950) has given the maximum sizes and size-progression of the age-groups in successive years. Nair (1953) has noted that age-groups in the fishery "showed variations in their rate of growth" and subsequently stated (Nair, 1959) that length-frequency data "show differential rate of growth during the first year (Nair, 1953)". Apart frpm these nothing substantial is published hitherto on variations in the growth of this fish. Hence the present paper dealing with differences in its growth rate in successive years of its life in the fishery, those within each season and in between seasons, as well as different phases of its life-history may be of interest. The investigations were made during 1961-1964 at Cannanore, one of the important oil sardine fishing centres in the Malabar zone of the south-west coast of India