Journal of the Marine Biological Association of India

Some aspects of the biology of the ribbonfish Trichiurus lepturus Linnaeus.

Volume 20 Issue 1&2

P. S. B. R.James, T. R. Chandrasekhara Gupta and S. L. Shanbhogue

Abstract

The paper presents the results of studies carried on the age and growth, maturation, spawning, fecundity, sex-ratio and food of Trtchiurus leptums obtained from the trawl net catches landed at Mangalore, southwest coast of India. The relationship between the snout-vent length (SV length) and standard length (SL) was found to be Y = 146.94 + 2.0359 x where' Y ' is the snout-vent length and 'X’ is the standard length. The life span of the species was estimated to be at least six years, attaining S.V. length of 120 mm at the end of first year, 216 mm at the end of second year, 276 mm at the end of third year and 336 mm at the end of fourth year. The minimum size at first maturity for females was found to be 140 mm S.V. length and for males 130 mm. The species spawns throughout the year with a protracted spawning period and the individual spawning more than once. The number of mature ova is found to vary between 1,000 and 1,34,000 in the fishes of size from 136 to 381 mm S.V. length. The relationship between fecundity and S.V. length, fish weight and ovary weight were calculated. Studies on sex-ratio distribution indicated highly significant dominance of females. Teleosts, prawns and shrimps formed the important food of the species. The salient features of the present observation with those of earlier studies which were mainly based on the fishes obtained from the inshore area 'were compared and discussed.

Date : 31-12-1978