Age, Growth, Reproduction and Fecundity of the Sharpsnout Seabream (Diplodus puntazzo Walbaum, 1792) in the Black Sea Region

Abstract

In this study, the Sharpsnout Seabream (Diplodus puntazzo) population parameters (age, sex composition, length-weight relationship (LWR), age-length relationship, growth parameters, condition factor, gonadosomatic index, reproductive) of the sharpsnout seabream (Diplodus puntazzo) in the southern Black Sea Region have been investigated. In the study carried out between April 2018 and March 2019, 276 sharpsnout seabream were sampled and the average length and weight were calculated as 30.0 cm and 463.9 g, respectively. Male and female ratio was determined as 1:1.32 (P>0.05). Age of fish varied between 0-9 years. The von Bertalanffy growth parameters were L-infinity=48.1 cm, k=0.2656 year(-1) and t(0)=-1.6587 year for all individuals. The LWR was found as W=0.0399 L-2.7212 for all individuals. Total mortality rate (Z=0.560), natural mortality rate (M=0.501) and fishing mortality rate (F=0.059), growth performance index (phi'=2.73) and condition factor value (K=1.55) were calculated. The maximum GSI value was 6.83 in September. Mean relative fecundity was calculated as 14695.4 eggs / 1g. The mean egg diameter was calculated as 486.83 1..tm. This study is very important in terms of being the first study on this species in the Black Sea and will provide a source for future studies.