Euthynnus affinis affinis (Cantor) in the Vizhingam fisheries

In the fisheries of Vizhingam seven different types of tuna are distinguished. They are Auxis thazard (Lacepede), Auxis thynnoides Bleeker, Sarda orientalis (Temminck and Schlegel), Kishinoella tonggol (Bleeker), Neothunnus macropterus (Temminck and Schlegel), Katsuwonus pelamis (Linnaeus) and Euthynnus afinis afJinis (Cantor). A comprehensive account on their identification is given by Jones and Silas (1960). The little tunny or mackerel tuna (Euthynnus afinis affinis) is commercially one of the most important species at Vizhingam. The fisheries of the little tunny have assumed importance in recent years owing to the great demand for dried tuna in India and abroad. Research on the biology and fishery of the little tunny has been but meagre and practically no information is available on these subjects. In this paper some aspects of its biology are dealt with based on material from Vizhingam.