Research Article: Study of some biological aspects and population dynamics of striped piggy fish, Pomadasys stridens (Forsskal, ۱۷۷۵), from Lake Timsah, Egypt

The present investigation was carried out to study the age, growth, length-weight relationship, spawning season, length at first sexual maturity, length and age at first capture, mortality, and growth performance of the commercial striped piggy fish, Pomadasys stridens (Forskål, ۱۷۷۵), inhabiting Lake Timsah in Egypt. Fish specimens collected during the period from January ۲۰۲۲ to December ۲۰۲۲ were selected to represent all fish size categories in the catch. The age distribution covered age groups I to V. Total length ranged from ۸ to ۱۷.۸ cm, while total weight varied from ۱۰.۵۷ to ۸۷.۶۵ g. There was no significant difference between the length–weight relation (LWR) parameters of sexes and pooled data. The overall LWR was found to be W=۰.۰۱۱۲×L۳.۰۴۹۶. It was found that both males and females matured at a total length of about ۱۲.۳cm for males and ۱۲.۷ cm for females. The natural spawning period for P. stridens in Lake Timsah is at the end of spring and early summer, from May to July. The von Bertalanffy growth parameters were not significantly different between males and females. The model parameters for both sexes were:  L∞=۲۱.۰۱ cm, K= ۰. ۲۴۵, and t۰= -۱.۵۴۷۵. The annual rates of total, natural and fishing mortality for male and female P. stridens were calculated as ۲.۰۴۰۵ Yr–۱, ۰.۶۳۶۷ Yr–۱, ۱.۴۰۳۸ Yr–۱ and ۲.۰۱۵۱Yr–۱, ۰.۷۰۳۵ Yr–۱, ۱.۳۱۱۶ Yr–۱ , respectively. The current exploitation rate 'E' was estimated at ۰.۶۹ and ۰.۶۵ for males and females.

کلیدواژه ها:

Striped piggy ، Growth ، Length-weight relationship ، Mortality ، Lake Timsah