The studies were conducted in the coastal areas of water bodies located in the Volga, Volodar and Krasnoyarsk districts of the Astrakhan region.
The aim of the work is to assess the condition of spawning grounds, visually observe the approaches and spawning of fish producers, search for clutches of fish eggs on the spawning substrate, and determine the timing of fish spawning by incubating eggs in laboratory conditions.
Positive anomalies of daytime air temperatures observed since the end of March contributed to the warming of the water, which had a favorable effect on the development of forage zooplankton - an important food link for many fish species at the larval stages of development.
In water bodies, small producers of pike perch 32-35 cm long, with gonads at the III and IV stages of development, asp producers up to 40 cm, with gonads at the IV stage of development were found. The presence of noticeable quantities of common perch at the stage of gonad fluidity and silver carp was also noted.
Rarely encountered pike eggs were largely covered with saprolegnia (a fungal disease), which may indicate sharp daily changes in water temperature. Silver carp eggs were found. Common perch eggs were located in the water column mainly on the surface of the substrate. Unstable water level conditions lead to drying out of some of the egg clutches.
At the beginning of the second five-day period of April, the first prelarvae hatched, which indicates that the spawners will spawn in the studied area of the eastern part of the Volga Delta in the third ten-day period of March 2025.
The success of fish spawning in the spring of 2025, such as the spawning run, spawning, incubation of the laid eggs, hatching and fattening of larvae, will depend on the hydrological regime and weather conditions, and in small well-warmed eriks, spawning events can occur at an earlier date than in the Volga and its large watercourses.
Press service of VNIRO
мелководных объектах Астраханской области
мелководных объектах Астраханской области
мелководных объектах Астраханской области
мелководных объектах Астраханской области
мелководных объектах Астраханской области
мелководных объектах Астраханской области
мелководных объектах Астраханской области
мелководных объектах Астраханской области
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