Biological Parameters of Trachurus mediterraneus (Carangidae) off the Coast near Southwestern Crimea during the Period from 2020 to 2022

This paper presents the results of a study of the sex and size–age structure, growth, maturation, and dynamics of the gonadosomatic index and condition factor of Mediterranean horse mackerel Trachurus mediterraneus (Steindachner, 1868) in the coastal waters of the Black Sea off southwestern Crimea in 2020–2022. A total of 2234 specimens have been studied, 879 of them being sexed. The male-to-female ratio (1.00 : 1.02) in the catches did not statistically differ from 1 : 1; no differences in growth rates have been found between the sexes. The maximum total body length is 26.1 cm for an individual aged 8+. Parameters of the von Bertalanffy equation for the whole sample were as follows: asymptotic length, 21.9 cm, asymptotic weight, 86.3 g, and growth constant, 0.24 year–1. Fifty percent of females mature at a total body length of 12.43 cm at age 1+ and 50% of males at a total body length of 12.46 cm at the same age. The peak of the spawning period is observed in July and the peak values of the condition factor in November.