The effect of monsoon on fish larva assemblage changes in Gowatr Bay, North Oman Sea

The study and research of abundance and diversity variation of fish larva (Ichthyoplankton stages) was done in Gowatr Bay during autumn 2006 - summer 2007. Five stations were selected for sampling, and Bongo-Net with 300µ mesh size was towing from bottom to surface. During of survey, totally 531 larvae belong to 11 families were collected and identified. The mean abundance estimated 12.17 larvae per 10 m^2, in which three fish larva family including: Gobiidae, Clupeidae and Engraulidae were dominant (86% of relative abundance). The result showed that there was significant differences between pre and post-monsoon fish larvae abundances (p.05). In pre-monsoon 4 families were identified of which Clupeidae introduced as indicator group, whereas in post-monsoon 10 families were identified and Gobiidae was indicator family, accompany with increase of diversity. PCA result was shown, temperature as the main factor affected on fish larvae assemblage was found with a significant decrease of 11.9 °C after monsoon phenomenon