Determination of Growth and Reproduction Characteristics of Garfish (Belone euxini Günther, 1866) in the South Black Sea

Abstract

Abstract In this study, it was aimed to determine some basic population parameters (age, length, sex composition, length-weight relationship, age-length relationship, growth parameters, condition factor, GSI) of garfish (Belone euxini, Günther, 1866) in the Southern Black Sea Region coasts. A total of 917 fish were sampled in the study, and their average length and weight were determined as 37.31 ± 0.147 cm, 58.74 ± 0.876 g. Theirs ages were between 1 to 7 and 40.89% of fish consisted of 3 years old. Sex ratio (F:M) is determined as 1:1.81. Length-weight relationship equations W = 0.0005*L3.196, W = 0.0009*L3.040, W = 0.0005*L3.196 for females and males and all, respectively. Asymptotic length (L∞) and the growth coefficient (k) were estimated at 78.20 cm and 0.119 year− 1 for females, 69.82 cm and 0.120 year− 1 for males and 92.06 cm and 0.082 year− 1 for all indivuduals. Instantaneous total mortality, natural mortality and fishing mortality rates were calculated as Z = 1.02 year–1, M = 0.16 year–1, and F = 0.86 year–1 for combined sexes. Exploitation rate was E = 0.84. The population of Belone euxini was affected by fishing during the study period, according to the estimated E values. According to the GSI values ​​calculated for Belone euxini, it was determined that reproduction started in July and continued until October.