Growth parameters and mortality rate of Neogobius caspius (Eichwald, 1831) in southern part of the Caspian Sea (Teleostei: Gobiidae)

In the present work, due to the lack of information on population dynamics of the Caspian goby, Neogobius caspius, we aimed to investigate growth and mortality parameters of this species captured from the south part of the Caspian Sea (Mazandaran Province) during a year from April 2014 until March 2015. Growth and mortality rates were assessed using age calculation. By using least squared method, L∞ and K of the specimens were 16.83 cm and 0.67 year-1 in female specimens and 17.76 cm and 0.83 year-1 in male specimens, respectively. Comparison of the growth curves resulted by likelihood ratio method showed a significant difference between two sexes (P<0.05). The maximum estimated age for female was 4.47 years old while 3.61 year for male. According to Pauli’s empirical equation, natural mortality rate was calculated 1.25 and 1.41 year-1 for female and male, respectively. Sex ratio (male: female) was 1: 1.14 indicating no significant difference (P>0.05). Based on the results presented here, the present investigation can be regarded as basis for future studies on Caspian goby. In the present work, due to the lack of information on population dynamics of the Caspian goby, Neogobius caspius, we aimed to investigate growth and mortality parameters of this species captured from the south part of the Caspian Sea (Mazandaran Province) during a year from April 2014 until March 2015. Growth and mortality rates were assessed using age calculation. By using least squared method, L∞ and K of the specimens were 16.83 cm and 0.67 year-1 in female specimens and 17.76 cm and 0.83 year-1 in male specimens, respectively. Comparison of the growth curves resulted by likelihood ratio method showed a significant difference between two sexes (P<0.05). The maximum estimated age for female was 4.47 years old while 3.61 year for male. According to Pauli’s empirical equation, natural mortality rate was calculated 1.25 and 1.41 year-1 for female and male, respectively. Sex ratio (male: female) was 1: 1.14 indicating no significant difference (P>0.05). Based on the results presented here, the present investigation can be regarded as basis for future studies on Caspian goby. In the present work, due to the lack of information on population dynamics of the Caspian goby, Neogobius caspius, we aimed to investigate growth and mortality parameters of this species captured from the south part of the Caspian Sea (Mazandaran Province) during a year from April 2014 until March 2015. Growth and mortality rates were assessed using age calculation. By using least squared method, L∞ and K of the specimens were 16.83 cm and 0.67 year-1 in female specimens and 17.76 cm and 0.83 year-1 in male specimens, respectively. Comparison of the growth curves resulted by likelihood ratio method showed a significant difference between two sexes (P<0.05). The maximum estimated age for female was 4.47 years old while 3.61 year for male. According to Pauli’s empirical equation, natural mortality rate was calculated 1.25 and 1.41 year-1 for female and male, respectively. Sex ratio (male: female) was 1: 1.14 indicating no significant difference (P>0.05). Based on the results presented here, the present investigation can be regarded as basis for future studies on Caspian goby.