Effect of climate change on growth and reproduction of nile tilapia (Oreochromis niloticus, l.) from bahr shebeen canal, delta of egypt

Abstract

Global warming was noticed in the last five years, and its effects on various biological processes of animals are imminent. Therefore, this study was carried out to examine such effects on the growth and reproduction of Oreochromis niloticus, from Bahr Shebeen Canal. Growth in length of fish was significant, where r2 was 0.93 and 0.97 for males and females, respectively. The weightlength relationship exponent was found to be 2.5842 and 2.7994 for males and females, respectively. The samples under study were found to fall into 5 agegroups. The condition coefficient showed a seasonal decrease in going from winter to spring for both sexes. The sex ratio for males and females O. niloticus was found to be 1:0.53. GSI values for both sexes indicated that sexual maturity is achieved at a smaller length and younger ages in females than males. Seasonal variations of GSI values indicated multiple spawning. Fecundity showed a gradual decrease in going from winter to autumn. It was also noticed that it decreased with the excessively high temperatures of the summer months. Those predictions were discussed and compared to previous studies, which could be related to the prevalent warmer weather.