Abundance and diversity of fish larval assemblages in Iranian waters of the Oman Sea

A survey on the abundance and diversity of fish larvae along the Iranian waters of the Oman Sea, extending from Hormuz Strait to Gowatr Bay, was carried out in 2009 (before and post monsoon). Fish larva were collected by a Bongo net (300 μ mesh size) and temperature, salinity, dissolved oxygen, pH, chlorophyll-a, clarity, nitrate, nitrite, silicate and sulfate by oceanic data recorder (CTD) and Rosette oceanography instrument were measured. In total, 26 fish families were identified and their abundance calculated as 768 individuals per m2. In pre-monsoon, 9 families were identified with Pomacentridae as dominant taxon. But in postmonsoon, 23 families were identified in which Myctophidae was dominant. The Shannon index was calculated as 0.583 ± 0.31 in pre-monsoon and 0.865 ± 0.73 in post-monsoon. The result of Principle Component Analysis (PCA) revealed a higher diversity among ichthyoplankton in post-monsoon compared to that of premonsoon. The abundance of fish larva was correlated with chlorophyll-a in postmonsoon, whereas samples from pre-monsoon were more positively correlated with in nutrients.