Population parameters and reproductive biology of Otolithes ruber (Bloch & Schneider, 1801) (Teleostei: Sciaenidae) in the northern Makran Sea

Abstract

This study was conducted to determine some biological aspects of the tiger tooth croaker Otolithes ruber in the coastal waters of the northern Makran/Oman Sea. Monthly total length frequency data of O. ruber were collected by bottom gill-net and bottom trawl from August 2016 to August 2017. ELEFAN-I method in the software package FISAT-II was used to analyze of the length frequency data. The total length and weight relationship demonstrated that growth in this species is negative allometric. The asymptotic total length ( TL∞ ) was estimated as 60 and 65cm for males and females, respectively. The growth parameter K was calculated as 0.43 y -1 for males and 0.40 y -1 for females. The total mortality, natural mortality and fishing mortality rates were estimated as 1.85, 0.83 and 1.02 for males and 1.37, 0.77 and 0.60 for females. The exploitation rates were estimated at 0.44 for males and 0.55 for females. The sex ratio revealed that it was not a constant 1:1 throughout the year, with 58 % for females. The Gonado-Somatic Index (GSI) showed upswing trend from January to June, and the maximum GSI was 7.1±0.6 in April. The recorded result showed that the tiger tooth croaker can spawn all year round and have a spawning peak from April to June (spring season). The Lm 50 % was estimated at 43.3cm of total length.