Aspects of Population Dynamics of Tiger Tooth Croaker, Otolithes ruber (Bloch and Schneider, 1801) from Northwest Arabian Gulf, Iraq

Abstract

The present study consists of the growth, mortality, relative yield recruit and virtual population analysis of tigertooth croaker, Otolithes ruber from Iraqi marine waters, northwest Arabian Gulf between February 2020 and January 2021. Analysis of population dynamics employed methods fitted in FiSAT II software using pooled length-frequencies. A total of 3835 individuals of O. ruber ranged from 17.0 to 60.0 cm have been collected. The exponent (b) of the length-weight relationship was found to be 2.755. The von Bertalanffy growth parameters (L∞ and K) were estimated as 68.5 cm and 0.36, respectively, while the growth performance index (Ø') was 3.228.  The total mortality (Z) was calculated as 1.10, while the natural and fishing mortality rates were 0.69 and 0.41, respectively, and the current exploitation rate (Ecurrent) was 0.38. Fish were recruited to the fishery at a mean size of L50= 20.55 cm. The recruitment pattern of O. ruber was continuous throughout the year with two major peaks. The analysis of yield-per-recruit (Y/R’) indicates that the current exploitation rate was below the biological target reference points (E0.1 = 0.40 and Emax= 0.53), refer to the stock of O. ruber is underexploited. The 27 cm length group was more vulnerable to fishing and more harvested according to virtual population analysis. sLength at first capture was higher than the length at first maturity of the species in the region. For management purposes, more yields could be obtained by increasing the mesh sizes of the nets employed in the fishing of the species.