~ 308 ~ International Journal of Fisheries and Aquatic Studies 2016; 4(6): 308-313 ISSN: 2347-5129 (ICV-Poland) Impact Value: 5.62 (GIF) Impact Factor: 0.549 IJFAS 2016; 4(6): 308-313 © 2016 IJFAS www.fisheriesjournal.com Received: 11-09-2016 Accepted: 12-10-2016 PSCHPD Rani Department of Zoology, Andhra University, Visakhapatnam PPN Vijay Kumar Department of Zoology, Andhra University, Visakhapatnam, Andhra Pradesh, India K Rushinadha Rao Department of Zoology, Andhra University, Visakhapatnam, Andhra Pradesh, India U Shameem Department of Zoology, Andhra University, Visakhapatnam, Andhra Pradesh, India Correspondence PPN Vijay Kumar Department of Zoology, Andhra University, Visakhapatnam, Andhra Pradesh, India Seasonal variation of proximate composition of tuna fishes from Visakhapatnam fishing harbor, East coast of India PSCHPD Rani, PPN Vijay Kumar, K Rushinadha Rao and U Shameem Abstract The present study was carried out to assess the proximate composition of tuna fish Kawa kawa (Euthynnus affinis) and frigate tuna (Auxis thazard) from Visakhapatnam fishing harbor, East Coast of India. These fishes inhabit coastal waters and have preference staying in relatively warm water. In the present study the proximate chemical composition and seasonal variations of moisture, protein, fat and ash in marine fishes Euthynnus affinis and Auxis thazard were recorded during three different seasons. High moisture content was observed during pre-monsoon seasons (77.01±0.16 in E. affinis and 79.71±0.36 in A. thazard), while high protein concentration was seen in monsoon season (25.16±0.10% and 23.34±0.21%) in both E. affinis and A. thazard species. Whereas high mean concentration of fat was found in post-monsoon season in the case of E. affinis, recording 1.37±0.16% and in monsoon season in the case of A. thazard (1.25±0.07%). High ash percentage was noted in pre-monsoon season in E. affinis (1.13±0.14%) and in post-monsoon season in A. thazard (1.01±0.27). Keywords: Proximate composition, euthynnus affinis, auxis thazard, food and agriculture organization 1. Introduction Fish constitutes a very important component of the diet for many people and often gives the much needed nutrient that is not provided by the cereal-based diets [1] . Nutrition has been mentioned as one of the most important reasons why consumers are attracted to seafood [2] . Seafood, especially finfish provide a major source of essential nutrients such as proteins, vitamins, fats and minerals which help in the maintenance of life to man [3] . Basically, tuna meat is considered highly nutritive owing to its content of essential amino acids, protein and fat [4] . Tuna fish is well known for its rich food value as it contains elevated levels of Omega-3 polyunsaturated fatty acids, which has many health benefits like it lowers the risk of heart diseases, reduces cholesterol levels, regulate blood pressure, prevents arteriosclerosis and there are many other health benefits. Tuna also contains minerals like phosphorous which are important for the nervous system and iodine which is conducive for balanced growth. Besides, it also contains vitamins like niacin and vitamin B12 necessary for cell growth and proper metabolism of fatty acids and cholesterol [5] . Tunas are among the largest and most specialized and economically imperative of all fishes [6] . In India, tuna fisheries are concentrated mainly on the coastal region while offshore tuna fishery resources are yet to be exploited commercially. There is a considerable increase in tuna fish exports from India from 16,627 t in 2005-2006 to 23,778 t in 2006-2007 and the tuna export realization grew from Rs 693.1 million in 2005-2006 to Rs 1303.8 million in 2006- 2007. Chilled tuna is the highest unit value earning item, while larger quantities of tuna are exported in frozen form. Major form of chilled tuna exported is whole tuna, yellow fin loins and gutted tuna (MPEDA) [7] . The Indian Ocean contributes 19% of the world tuna catch [8] and they are the fourth major internationally traded fish commodity contributing 7.6% of the international fish trade in value terms [9] . The species, which contributed to tuna fisheries are E. affinis (51%), A. thazard (16%), A. rochei (3%), Katsuwonus pelamis (9%), T. tonggol (9%), T. albacares (10%) and Sarda orientalis (3%) [10] . The size range of the fish in the catch was; E. affinis, 24-60 cm, A. thazard, 20-54 cm, T. albacares, 28-90 cm, S. orientalsis, 36-54 cm and A. rochei, 22-34 cm.