Species composition in the Carangidae family during dark and light periods using the bottom trawl survey

The study aimed to estimate the effect of ecological factors such as day and night on catch species composition in fishing landings in the perisan Gulf in May 2016. In this study, were catched about 34937.18 kg marine speceis and identified of 64 groups of species and family including 56 groups of bonyfishes, 6 groups of invertabrate, 2 groups of cartilage fishes. Meanwhile, the Bushehr, Hormozgan and Khuzestan province catched 22696.38, 10611.5 and 1629.3 kg respectively. The highest percentage of catches occuored in the stations sampled including Nemipteridae, Rey Fishes, Suaridae, S. Guttatus, Platycephalus Indicus and Sphyraenidae. In terms of catch weight Diagramma  pictum, Saurida tumbil and Rey fishes accounted for over 10% of the total catches. Result of catch per unit fishing effort (CPUE) for the Persian Gulf during day and night time showed that 22 groups of fishes have a significant difference, although there was no significant difference in the catches of 27 groups in day and night, which couse to have different patterns of migration during the day (lighted conditions) and night (dark conditions) and short sampling period of this research. According the little biological information during day and night for implementing and stock assessment models, The results of this study can be used to provide the target species in the trawl using during periods of light and dark.