Journal of the Marine Biological Association of India

Observations on some aspects of biology of the Croakers Johnius (Johninieops) dussumieri (Cuvier) and Johnius (Johnius) carutta Bloch from Kakinada.

Volume 21 Issue 1&2

V. Sriramachandra Murty

Abstract

Observations on some aspects of biology of Johnius dussumieri and J. carutta are made from trawler catches of Kakinada. It is shown that J. dussumieri spawns during March-August period. This species attains first maturity at a total length of 110 mm. There is a predominance of females in larger length groups. The length-weight relationship of J. dussumieri follows the equation log w = -4.84511 -|- 2.96347 log L. The fluctuations in relative condition factor seem to be related to gonad cycle.

Individuals of J. carutta attain first maturity at a total length of 155 mm. This species is a fractional spawner releasing the ripe ova in two spawning acts during the single spawning season which appears to extend from January to June. In this species also, as in J. dussumieri, there is a predominance of females in larger lengths. The length-weight relationship in J. carutta is calculated to be log W = -5.43389+ 3.23343 log L

Date : 31-12-1979