Determination of the reproductive biology of whiting (Merlangius merlangus Euxinus, Nordmann, 1840) by histological method in the Eastern Black Sea

The aim of this study was to compare the macroscopic and microscopic stages of the whiting in the Eastern Black Sea Region and to provide more realistic information about the reproductive strategy and reproductive period of the species. In addition, the length, age, sex composition, reproductive characteristics, HSI, GSI, condition factor, the length at first sexual maturity (LM50), annual and partial fecundity and egg diameters were determined. The lengths of 1579 whiting samples which were collected in 12 months period between March 2017 and February 2018 ranged from 7,5 cm to 32,6 cm and the mean length and the mean weight were calculated as 14,49±2,85 cm and 26,05±20,95 g, respectively. The sex ratio (M/F) was determined as 1/1,31. Reproduction periods were observed twice in a year between March-July and October January. Total annual fecundity and partial fecundity were estimated as 107162±109768 and 18882,2±20193, respectively, also the average egg diameter was found as 0,74±0,440 mm. The length at first sexual maturity (LM50) was calculated to be 13,32 cm in females and 12,57 cm in males. If the results obtained in the study are applied in the management of whiting stocks, it will contribute to the sustainability of the stocks and fishing of this species.