بررسي انتشار جغرافيايي گونه هاي موجود پريان ميگوها در استان آذربايجان شرقي

A Study of geographical distribution of fairy shrimps {Anostraca) in East Azerbaijan province (Iran).

A study of geographical distribution of fairy shrimps (Anostraca) in East Azerbaijan province of Iran was accomplished during 2004-2005. Sampling stations were chosen based on gathering information from local authorities and a number of visits were made for assurance of the presence of fairy shrimps. Some climatic and physico-chemical factors of vernal pool waters inhabited by fairy shrimps were determined. Among 18 studied basins and pools, 5 species of threatened Anostracans were identified in different location as follows: Chirocephalus skorikowi (Chirocephalidae) was fund in Aigher-Goli basin Bostanabad, Branchinecta orientalis (Branchinectidae) in Zainal-Hajilou near Osko and Teymoorlou near Azarshahr and Alaghya near Hashtrood, Streptocephalus torvicornis (Streptocephalidae) in Ghom-Tappeh near Sophian, Branchinella spinosa (Thamnocephalidae) in Khasellou near Azarshahr, and Artemia spp. (Artemiidae) coexisting with B. spinosa in Khasellou pool. However, other species may also exist in these pools. In these vernal pools, fairy shrimps were found from early April at water temperature of 12°C to late June at water temperature of up to 28°C, with pH range of 6.5-8.3 and salinity range of 0-32 mg/1. The mean number of cysts per female fairy shrimp in Aigher-Goli, Teymoorlou and Ghom-Tappeh pools were: 305±5.9, 410±13.6, 477±10.5, respectively, indicate their high fecundity. Furthermore, mean diameter of cysts of fairy shrimps in Aigher Goli, Teymoorlou, Ghom-Tappeh and Zeinal- Hajilou were found to be : 356 ± 8.8 (mu), 320 ± 11.5(mu), 307 ± 15.6(mu) and 344 ±7.4(mu) respectively, which indicate their suitable size for fish larvae feeding specially after decapsulation. Color of adult fairy shrimps ranged from translucent whitish to gray, blue or green, reflecting the content of food supply, and was usually constant among the individuals belonging to each pool. Coexisting animal fauna were: tadpole, daphnia ephipium, cyclops, chironomid larvae, dragonfly larvae, aquatic beetle, argironecta aquatica.