Some Parameters of Population dynamics of Palaemon adspersus (Rathke, 1837) in the South-east of the Caspian Sea (Gorgan Bay)

Abstract

In this study, the population dynamics parameters of Baltic prawn, Palaemon adspersus were investigated in South-east Caspian Sea (Gorgan Bay). Specimens were collected monthly by using seine net (mesh size 5mm) between April 2016 and October 2016. Altogether, 434 prawns (163 females, 271 males) were captured. Maximum length, carapas length and weight were 76.20 mm, 18.27 mm and 5.621g for females and 62.69 mm, 14.06 mm and 2.306 g in males, respectively. Maximum length frequency was observed in total length range of 65-69 mm and 45-49 mm for females and males, respectively. Sex ratio for collected prawns was 62% for males and 38% for females. The von Bertalanffy growth equation was calculated as Lt=66.15[1-e-0/71(t+0.18)] for males, Lt=78.75[1-e-1/10(t+0.36)] for females and Lt=78.75[1-e-0/79(t+0.51)] for population. Growth performance (Φ') was higher (3.88) in females than that of males (3.49). Maximum calculated age was 4.05 and 2.37 years for males and females, respectively. The estimated value for total mortality (Z), natural mortality (M) and fishing mortality (F) were 3.74, 1.36 and 2.38 per year for females and 2.88, 1.08 and 1.80 per year for males, respectively. Exploitation rate (E) was calculated 0.63 and 0.64 for males and females, respectively.

Keywords

• palaemon adspersus
• growth function
• mortality rates
• gorgan bay