Studies on seasonal variation in the biochemical composition of the Indian shad, Tenualosa ilisha (Hamilton, 1822)

Abstract

An year round study on the macro and micro-nutrient constituents of the Indian shad (Tenualosa ilisha) was carried out. The
average values of the proximate composition recorded were: moisture – 68.16%, ash – 1.42%, protein – 16.27%,
fat – 12.04%, calcium – 55.09%, phosphorous – 184.58%, sodium – 66.10% and potassium – 179.95%. The summation of
moisture and fat content was 80%. The correlation coefficient (r) between moisture and fat content obtained was – 0.987
indicating an inverse relationship. The correlation coefficients between weight and moisture and weight and fat content
recorded were 0.670 and 0.7181 respectively. The maximum moisture content was observed in January (74.22%) when the
average weight of the sample was 357.83 g and the minimum was found in September (58.82%) when the average weight of
the sample was 788.35 g. The lowest fat content was recorded during January to April, whereas, the maximum fat content
was found during July to September. In the rest of the period, the average fat content was 11.45 %. The proportion of calcium
and phosphorous in the flesh of hilsa was found to increase with increase in size of the fish. On the other hand, sodium, the
most vital tissue component of fish, decreased considerably with growth of the fish, whereas no definite trend of variation
was observed in potassium content of the fish.