Ichthyoplankton of the Black Sea during the Period of Mass Spawning of Warm-Water Fish Species

The species structure and spatial distribution of ichthyoplankton in July–August 2019 during the period of mass spawning of warm-water fish species are presented. The material was collected at the shelf and in the deep waters of the Black Sea off the Crimean Peninsula and along the Caucasian coast. In ichthyoplankton, eggs and larvae of 29 species of fish from 19 families were identified. The indices of species richness in the open sea and in the coastal areas were similar. European anchovy Engraulis encrasicolus (Linnaeus, 1758) dominated in ichthyoplankton, its maximum egg abundance reached 260 ind./m2, larvae abundance, 117 ind./m2. The highest spawning efficiency of E. encrasicolus was observed in coastal waters heated up to 26–27°C near the Caucasian coast and on the western shelf of the Crimean Peninsula, where the ratio of the number of larvae to the number of eggs was 30% in the samples. An increased population density of ichthyoplankton was also noted within the Crimean anticyclonic gyre, the shelf thermodynamic formation most stable in time. We assume that favorable conditions were formed there for spawning and survival of fish at the early stages of development.