Identification of distribution of Macrobrachium Nipponense in freshwater ecosystems and coastal waters of Golestan Province,Caspian Sea

Abstract

Distribution of freshwater shrimp (Macrobrachium nipponense) in the freshwater ecosystems such as Alagol, Almagol, Ajigol lagoons, Gomishan lagoon and Gorganrud River. Sampling were done from may 2009 to my 2010 parameters such as, length frequency, growth rate, sampling, feeding, environmental factors and sedimentation were investigated. 3689 females and 8551 males were collected and biometrical parameters were recorded. Total length ranged between 3.2 to 98.7 mm. The parameters b of length-weight relationship in Alagol, Almagol, Ajigol were 3.49, 3.15, 3.45, 3.22 and 3.22, 3.28 for male and female, respectively. It shows in all lagoons for male and female growth is positive Allometric. Spawning period was from May to June. The length first at maturity (total and/or carapace) for three lagoons was 50.5 mm and 133 mm, respectively. The minimum and maximum of egg volume were 0.12 mm3 in Ajigol and 0.07 mm3 Alagol, respectively. The relationship between fecundity and length was found to be linear regression models for Alagol, Ajigol and nonlinear regression models for Almagol lagoon. Result showed that this species is omnivorous. The minimum and maximum temperature was 6.5ْ C in fall and 33ْ C in summer. The lowest and highest fluctuations of pH level in Ajigol and alagol lagoons were 8.2-9.2 and 7.2-9.8. Among three lagoons, the most EC was 5.9 Ms/c in Alagol lagoon. The Gorganrud River shows the maximum EC, 16.7 Ms/c.