Journal of the Marine Biological Association of India

Length-weight relationship, growth and reproductive biology of Narke  impennis (Annandale, 1909) (Pisces: Narkidae) of Visakhapatnam coast, Western Bay of Bengal, India 

Volume 60 Issue 2

V. Ravali, K. Sujatha and V. A. Iswarya Deepti

10.6024/jmbai.2018.60.2.2022-11

Abstract

A total of 250 spottail sleeper ray, Narke impennis caught from Visakhapatnam waters were analysed with respect to length frequency distribution, length -weight relationship, growth studies, length-at-first maturity, size-at- birth, sex ratio, gestation period and fecundity. Specimens ranging from 53 to 206 mm TL (132.833±0.132) including 137 males and 113 females, were collected from shrimp trawl and trammel net catches during June, 2015 to April, 2017. The length-weight relationship for females, males and combined sex was estimated as b <3, the growth is considered to be negative allometric. The asymptotic length (L∞) and VBGF growth constant (K) for spottail sleeper ray were estimated as 215.25 mm and 0.350 yr-1 respectively. Average condition factor was estimated as 2.514 for males, 2.449 for females, and 2.465 for combined sex. Length- atfirst maturity for females was estimated as 120 mm TL and 115 mm TL for males and the size-at- birth was estimated to range between 42 to 46 mm TL. Mature females in full vitellogenic activity showed 2 to 8 yellow-yolked ovarian eggs. Number of embryos ranged from one to six. Overall sex ratio favoured males at the rate of 1:0.8. This study presents the first detailed biological observation and growth studies of the spottail sleeper ray in Indian waters. 

Keywords

Spottail sleeper ray, growth studies, length-weight relationship, reproductive biology

Date : 30-12-2018