BIOLOGICAL FEATURES OF SYRMAN GOBY PONTICOLA SYRMAN (NORDMANN, 1840) FROM THE BILOSARAYSKA BAY OF THE AZOV SEA

Abstract

Syrman goby Ponticola syrman (Nordmann, 1840) is one is one of the valuable component of the Azov Sea ichthyofauna and it has importance in commercial and recreational fisheries. Articles deals with syrman goby’s biology features in Bilosarayska Bay of the Azov Sea. The results suggest that males are bigger than females in size – 9.1% and weight – 23.9% respectively. The gender ratio ranges from 1:1 throughout the study period. Age distribution is represented by two age groups – 1+ and 2+. Indicators of linear growth of the species have fairly equal rates in both males and females. Sexual dimorphism was expressed poorly, but in context of age variability, males in the second year of life are significantly different from females 1+ and 2+ and males 1+ at the level of 15.9–24.5. Most reliably distinctive features were measured on the head. The taxonomic composition of the 50-year-old food items that have been included in the feed spectrum of the syrman goby has increased from 8 to 14 taxons. The share of fish, shellfish and Polychaetas decreased, while the proportion of crustaceans increased. In terms of abundance, biomass, and frequency of occurrence, the species' nutrition is dominant Rhithropanopeus harrisi, Amphibalanus improvises, bivalve mollusk Abra segmentum and fish. The average value of the energy equivalent is dominated by fish, and the total – crustaceans. An analysis of the feeding spectra similarity of the syrman goby with the most abundant species of the Gobiidae family showed the greatest similarity with the monkey goby (Neogobius fluviatilis) and the round goby (Neogobius melanostomus).