CPUE in four types of traps: hokkaido, funnel net, opera house and cylindrical for catching Crayfish (Astacus leptodactylus) in culture ponds

This research was carried out to investigate the amount of CPUE for Astacus leptodactylus released in culture pools located in Hossein Kooh Shulam, belonging to the National Aquatic Research Center of Guilan province. Four types of traps including hokkaido, funnel net, opera House and cylindrical with mesh size of 8 mm were designed and built according to the biologic and ecologic characteristics of Crayfish in three culture ponds. Four traps of each type were used in ponds. The traps were connected longitudinal and continuously, and were monitored every 24 hours. The sampling period was 60 days. In total, 2002 Crayfish were caught of which, 986 were male and 1016 were female. The sex ratio (Male: Female) was calculated as 1: 1.3. The highest abundance percentage of caught fish was found in funnel net with 9.88% in the length class of 88-100 mm. The rate of CPUE for hokkaido, funnel net, opera house and cylindrical traps was 3.63, 2.43, 1.6 and 0.7, respectively that showed significant differences (p <0.05). According to the results, hokkaido trap had the best performance in terms of both CPUE and catching fish size in different length classes.