Study of Morphological characteristics and frequency of Dendrobranchiata larval shrimp in Artificial reefs of Khuzestan coasts, Bahrekan area

This study was done to identify larval stages and biodiversity of Dendrobranchiata planktonic communites in artificial reefs of Khuzestan coasts (Bahrekan area in Northwest Persian gulf) for one year from May 2011 to April 2012 monthly basis. Sampling was conducted using a plankton net with a spring 300 micrometers. Totally، from two superfamily: Penaeoidea and Sergestoidea، 3 families: Sergestidae، Luciferidae، Penaeidae were identified. From Penaeidae family، Metapenaeus affinis، Penaeus indicus and Parapenaeopsis stylifera species، from Luciferidae family، Lucifer hanseni specie and from Sergestidae family، Acetes sp specie were identified and introduced. Also larval density of identified species in different months and stations are calculated and determined Metapenaeus affinis specie (With the average of number per cubic meter in 1029±830) from Penaeidae family account for larval density is maximum in September. Finally، two abundance peak was observed that the first peak was in September and the second peak was in November. The maximum of relative frequency percentage in Penaeoidea superfamily related to mysisI stage and 62 percentage. The results obtained indicate that the artificial structures are well managed nursery area for Penaeidae shrimp. The maximum average value of Shanon-wiener index was in November (1. 36) due to the presence of all species in the same month. Simpson index was lowest in November، which confirms the above conclusion.