Biological particulars of the sun perch – Lepomis gibbosus (linnaeus, 1758) from the Cuciurgan reservoir-cooler

Abstract

The sun perch was recorded for the first time at the mouth of the Dniester in 1952. In the ichthyofauna of the Cuciurgan harbor in 1965. Starting with the second half of the 1960s, it was not recorded in the Cuciurgan refrigeration lake until the 2000s. From 2004, unique specimens were recorded, which probably hit, together with the water pumped from the Turunchuk arm. The share of sun perch in the control catches of Cuciurgan Refrigerating Lake increased from 0.5% in 2008 to a record 15.7% in 2017. The high abundance of sun perch in a short period is explained by the type of portioned reproduction, high prolificacy, early age of sexual maturity and also care for offspring. In the Cuciurgan reservoir, mature sun perch females weighing 7.2 g were captured, and with a weight of 13.4 g they were identified in stage IV of gonad maturation. The sun perch of the Cuciurgan Refrigerating Lake is characterized by a high growth rate, thus the maximum standard body length is greater than 17 cm with a mass of 220 g. A polynomial model was used to approximate the sun perch abundance monitoring data of degree IV (reliability coefficient R2 = 0.8211), which determines the characteristic of rapid growth of invasive fish species, then followed for 4 years a stage of stabilization of the population, after which it is characterized by a decrease in abundance, due to the appearance of a foreign species in the tank – the mud crab.