Dispersal, biodiversity and morphological characteristics of pelagic fish larvae in coastal waters of Hengam Island (strait of Hormoz)

This research have been conducted to investigate pelagic fish larval disperse, biodiversity and morphological features around Hengam Island. The island is located in south coast of Qeshm island in Strait of Hormoz. The bottom of vicinity water of Hengam Island is covered with coral reefs. Sampling carried out from late winter 2012 until late autumn using oblique sampling with 300 µm mesh plankton net. Fish larvae individuals were collected from near bottom to surface with three replicates from six selected sampling sites around the island. A total number of 6832 fish larvae were obtained from several families including Atherinidae, Carangidae, Cepolidae, Engraulidae, Hemiramphidae, Leiognathidae, Lethrinidae, Sillaginidae, Sparidae which consisted 48% of total abundance of larvae. The larval fish of the family Engraulidae was introduced  with 0.18  individual per 10 cube meter of filtrated water in autumn  as the dominant group. There was significant difference between seasons (ANOVA, p <0.05). Physicochemical factors were also measured at the time of sampling for each station.  Negative correlation was found between water temperature and abundance of almost pelagic families using Spearman correlation coefficient. Also morphometric and meristic characteristics of species of fish larvae were studied. Maximum amount of Shannon- Weaner index of diversity and dominance index of Simpson estimated in autumn and summer were estimated 3.37 and 0.72 respectively.