Journal of Environmental Biology

Influence of season and feeding intensity on fatty acid composition of wild cobia (Rachycentron canadum, Linnaeus, 1766) in the Dungun coast, Malaysia

T.A. Babatunde^1,4, S.M.N. Amin^2,3*, F. Md. Yusoff², N. Romano⁵, A. Arshad², Y.B. Esa¹ and M. Ebrahimi⁶ ? 

¹Department of Aquaculture, Faculty of Agriculture, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia

²International Institute of Aquaculture and Aquatic Science, Universiti Putra Malaysia, 71050 Port Dickson, Negeri Sembilan, Malaysia

³FAO World Fisheries University, Pukyong National University, Nam-gu, Busan 48547, Republic of Korea

⁴Department of Biology, Umaru Musa Yaradua University, Katsina, Nigeria

⁵Aquaculture/Fisheries Center, University of Arkansas at Pine Bluff, 1200 North University Drive, Pine Bluff, AR 71601, USA

⁶Department of Veterinary Preclinical Sciences, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia

*Corresponding Author Email : smnabd@gmail.com

Paper received: 16.01.2020 ?????? ???????????????????????????????????????Revised received: 25.02.2020 ???????????? ?????????????????????????Accepted: 14.08.2020

Abstract

Aim: This study investigates the variations in the fatty acid contents of cobia from Dungun coast, Malaysia with respect to changes in seasons and feeding intensity.

Methodology: Cobia samples were collected from a commercial fish landing center at Dungun, Terengganu, Malaysia to analyze the gut content and fatty acid composition of muscle and liver. Specimens were immediately dissected to determine sex as well as weight of food items in the stomach. Food items were identified and categorized as fish, mollusks and crustacean. The fatty acid composition in the liver and muscle tissue samples was determined by first extracting lipids using chloroform: methanol (2:1, v/v) mixture.? The physical water quality parameters (salinity, temperature, DO and pH) were measured in situ using an YSI multi parameter (model 6600, YSI, US).

Results: Saturated fatty acids (FAs) comprised the majority of FAs in the muscle, followed by monoenes, total poly-unsaturated fatty acids (PUFAs) (n-3) and then total PUFAs (n-6) with no seasonal variation in quantity. A similar trend was observed in the liver but the total saturated FAs were significantly higher during the inter-monsoon while total monoenes significantly accumulated during the monsoon. During low feeding intensity, there was a significant accumulation of PUFAs (n-6) in the muscle tissue (P < 0.05). Gut content analyses showed that cobia significantly increased the consumption of molluscs during the inter-monsoon (P < 0.05), although bony fishes dominated their diet throughout the year with no significant seasonal differences (P > 0.05).

Interpretation: Cobia lipids are composed of a significant quantity of omega-3 and omega-6 FAs, which have important health benefits. Environmental variability, especially salinity fluctuations and prey abundance that accompany seasonal changes, significantly impact the nutritional composition of cobia in Malaysian waters, however, their nutritional quality is maintained.

Key words: Cobia, Feeding intensity, Fatty acid, Rachycentron canadum, Wild cobia

Copyright ? 2020 Triveni Enterprises. All rights reserved. No part of the Journal can be reproduced in any form without prior permission. Responsibility regarding the authenticity of the data, and the acceptability of the conclusions enforced or derived, rest completely with the author(s).