Fishery and biology of the oil-sardine, Sardinella longiceps Val., off the Cochin coast

Abstract

The oil-sardine catches at Cochin showed wide-fluctuations during the years of this study. Relatively higher catches were obtained in 1960-61, 1966-67 and 1967-68, the highest bsing in the 1964-65 season. Poor fishery was recorded during the seasons 1959-60, 1962-63 and 1963-64. The highest catch per gear for 'thangu vala' (boat seine) was made in 1964-65. Studies on length frequency distribution indicated that the juvenile fish grew very fast during the first 12 months. The fishery was supported largely by the dominant O-year and 1-year classes; the 2-year and 3-year old ones were less abundant. During each year, commencing from 1959-60 through 1968-69, the bulk of the sardine catch was contributedbythel35,140,125, 45,100, 130, 150, 135,130 and 115 mm modal lengths respectively. Ova diameter studies revealed a short period of spawning, ova being released in a single batch. The peak season of spawning extends from June to August.