Distribution and biodiversity of fishes in bottom trawl in Iranian part of the Caspian Sea

The main objective of the present study was to determine spatial and temporaldistribution of bony fishes using bottom trawl in depths less than 100 m in Iranianwaters of the Caspian Sea, during 2007-2011. In 9 cruises, Rutilus frisii kutum(kutum), mullets, shads, Vimba vimba, Chalcalburnus chalcoies, Stizostedionlucioperca, Rutilus rutilus, Cyprinus carpio, Aspius aspius, Silurus glanis, Abramisbrama, Barbus capito and Esox lucius caught which kutum and mullets comprisedmore than 98% of total catch. In totally, mullets had high frequency in all seasons(except summer), but most kutum had been caught in autumn and winter. Spatialdistribution showed that most mullets were concentrated in depths <20 m. Incomparison to other seasons, the CPUE of mullets declined to the lowest level. Mostkutum was concentrated in depths <20 m in central region and common carp wasconcentrated in depths <20 m in eastern region. In the present study, the indices ofdiversity and evenness estimated in different seasons and regions. The highestdiversity was estimated in East region and winter.

کلیدواژه ها:

Distribution ، biodiversity ، bottom trawl ، Caspian Sea ، Ichthyology