Observations on the spawning behaviour of the Indianoil sardine, Sardinella longiceps Valenciennes,determined by ova diameter studies

Studies on the spawning habits of fishes form an integral part of fishery biological investigations. Nair (1959) published a detailed account on the spawning habits and early life history of oil sardine, Sardinella longiceps Valenciennes. Brief references on the spawning habits of oil sardine have also been made by Homell and Nayudu (1924) and Chidambaram (1950). These authors have drawn the conclusion that oil sardine have a prolonged spawning season. During the course of investigations carried out on the biology of oil sardine, observations were made on the occurrence of fish in various degrees of spent condition and this indicated the possibility of oil sardine releasing eggs in batches. So far there has been no published account to support this assumption. In search of further support for this assumption studies on ova diameter were conducted during the years 1960-62 at Mangalore, and the results obtained thereon have been presented in this paper together with the minimum size at first maturity.