Iranian Biology Society Journal of Animal Research (Iranian Journal of Biology) 2383-2614 35 2 2022 06 22 Investigation of some biometric and reproductive characteristics of Palaemon elegans in the Caspian Sea (Bandar Anzali coast) Investigation of some biometric and reproductive characteristics of Palaemon elegans in the Caspian Sea (Bandar Anzali coast) 89 100 2110 FA Sahar Khorshidi Sedehi Dept. of Biology, Faculty of Science, University of Guilan, Rasht, I.R.of Iran 0009-0008-4992-9124 Nader Shabanipour Biology Dept., Faculty of Science, University of Guilan Hamid Alaf Noveirian Fisheries Dept.,Faculty of Natural Resources, University of Guilan Journal Article 2021 08 08 Palaemon elegans shrimp is native to the Black Sea, which was introduced to the Caspian Sea during the years 1309 to 1313. In order to practice proper management, knowledge of biological characteristics and having sufficient and appropriate information about aquatic is very important. In the present study to identify the biological characteristics of P. elegans shrimp, 100 pieces of shrimp were captured by Landing net of 500 μ mesh size from coastal areas of the Caspian Sea. Some biometric parameters (total length, carapace length, live weight shrimp, diameter of eggs), absolute and relative fecundity, number of larvae, hatching percentage and their embryonic stages were examined and evaluated. The results showed that the mean total length, carapace length, live weight of shrimp (before and after removing eggs), live weight of eggs were 40/78 ± 6/12 and 10/41 ± 1/27 mm, 1/644 ± 0/41, 1/325 ± 0/36 and 0/129 ± 0/19 g, respectively. The average small and large diameter of eggs in the last embryonic stage was 0/447 ± 0/013 and 0/622 ± 0/079 mm, respectively. The mean absolute and relative fecundity were 931 and 566.30 ± 88/10, respectively, as well as the number of larvae 621± 79 and the hatching rate was 67/70 percent. The embryonic stages of this shrimp include six stages: fertilized egg, cell cleavage, eyed eggs, , nauplius with unequal eye, nauplius with equal eye (advanced nauplius in egg membrane) and finally the stage of zoea and the average duration of the embryonic stage was 11 days Palaemon elegans shrimp is native to the Black Sea, which was introduced to the Caspian Sea during the years 1309 to 1313. In order to practice proper management, knowledge of biological characteristics and having sufficient and appropriate information about aquatic is very important. In the present study to identify the biological characteristics of P. elegans shrimp, 100 pieces of shrimp were captured by Landing net of 500 μ mesh size from coastal areas of the Caspian Sea. Some biometric parameters (total length, carapace length, live weight shrimp, diameter of eggs), absolute and relative fecundity, number of larvae, hatching percentage and their embryonic stages were examined and evaluated. The results showed that the mean total length, carapace length, live weight of shrimp (before and after removing eggs), live weight of eggs were 40/78 ± 6/12 and 10/41 ± 1/27 mm, 1/644 ± 0/41, 1/325 ± 0/36 and 0/129 ± 0/19 g, respectively. The average small and large diameter of eggs in the last embryonic stage was 0/447 ± 0/013 and 0/622 ± 0/079 mm, respectively. The mean absolute and relative fecundity were 931 and 566.30 ± 88/10, respectively, as well as the number of larvae 621± 79 and the hatching rate was 67/70 percent. The embryonic stages of this shrimp include six stages: fertilized egg, cell cleavage, eyed eggs, , nauplius with unequal eye, nauplius with equal eye (advanced nauplius in egg membrane) and finally the stage of zoea and the average duration of the embryonic stage was 11 days https://animal.ijbio.ir/article_2110_c3535febaff29fcb7c0d20cbe94391c7.pdf