Length weight relationship and diet composition of yellowfin tuna (Thunnus albacares) landed in Negombo Fishery Harbour, Sri Lanka.

Yellowfin tuna (Thunnus albacares) is the second most economically important tuna species in Sri Lanka. Present study was focused on the determination of length-weight relationship and analysis of stomach contents of yellowfin tuna landed in Negombo fishery harbour. A total of 174 stomachs of yellowfin tuna (Thunnus albacares) were analyzed. The total length range of the observed yellowfin tuna was 50-169 cm and weight range was 10-86.5 kg. The diet of yellowfin tuna comprised of a variety of food items such as fish (55%), squids (30%), crabs (6%), shrimps (8%) and others (1%) indicating that it is a non-selective predator. The observed length weight relationship for yellowfin tuna was W= 0.000104 TL^2.6892.