A Biological Study of Gammaridae (Amphipoda) In the South Caspian Sea Basin (Iranian water) for Use in Fish Culture

A study was conducted to determine , feeding , reproduction in 12 stations in the Caspian Sea basin of Iran including Anzali wetland (lagoon), Ghorigol wetland, Neor lake , south Caspian coastal water (Iranian of shore), and several springs in Alborz mountains In addition sampling of Plankton and physical and chemical factors of the water body were also done in all stations. Special aquariums were designed to test the acclimation of the 7 amphipoda in pond culture. This process was performed from march 2001 to Feb 2003. The finding showed that while reproduction of Gammarus lacustris and Gammarus paricrenatus were only about 3 months , that Gammarus komareki lasted throught the year. From diet studies of intestine content have been showed that there is not a correlation between abundance and diversity of plankton with habitat for all species, except about Pontogarnrnarus maeoticus and P. borceae from Kelachi coast that had a high plankton abundance. Gammarus aequicauda (37.75 ± 31.04) and Obesogammarus acuminatus (49.07 ± 40.4) had the maximum of average eggs production while G. komareki had the lowest clutch sizes with mean about 7-8 eggs. Species tolerance to changes in environmental factors (Physical and chemical variation) were limited in the springs while those off coastal water species and Obesogammarus acuminatus were wider. In aquarium (laboratory) study, it was found that although Gammarus lacustris showed some growth but did not reproduce. Gammarus paricrenatus, in later stage of study, reproduced and grow in length during most experiment period. Although Gammarus komareki survived and a little active life, but was not able to acclimate itself to laboratory condition. The findings showed that four species P. maeoticus, P. borceae, O. acuminatus, and G. aequcauda , seems to be good candidate for acclimation study in warm water fish farms. Their living in the ponds can be enhanced by some limited alteration in substrate structure (P. maeoticus, P. borceae), presence of submerged aquatic plants (O. acuminatus) and higher water salinity (more than 2 ppt) for G. aequcauda..

Iranian Fisheries Science Research Institute

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