Fish-breeding and biological characteristics of herbivorous fish from a warm-water farm and the cooling reservoir of Primorye

In the first part of the article (Fish farm. and Fisheries, No. 12, 2025), the authors provided a fishery and biological description of silver carp and grass carp spawners from the cages of the Luchogorskaya Fish Hatchery Station of the TINRO Research Institute in Primorsky Krai. In the second part of the article, the authors summarized and analyzed the results of the last 25 seasons of growing fingerlings of these species and provided a description of natural population from the cooling pond. The body weight and survival rate of herbivorous fish grown in fry ponds under conditions of polyculture with carp fish and Amur predators were studied. The average weight of silver carp fry varied from 9.7 to 15.3 g when fed, and from 16.4 to 19.3 g for grass carp. The minimum weight of 4.5–5.5 g was recorded when the fish were kept without feeding and the ponds were fertilized with active sludge. The maximum weight of fingerlings is 20–80 g, and low survival rates are observed when feeding fish in seasons with a 10–25-day difference in the timing of planting carp and herbivorous fish and when fry of Chinese perch and Amur catfish weighing 0.3–1.7 g are released into ponds. The average survival rate of silver carp fingerlings over the years of research was slightly higher than that of grass carp, amounting to 16.1% and 14.7%, respectively. The herbivorous fish population of the cooling pond was formed as a result of regular stocking for 30 years and consists of individuals weighing from 5 g to 25 kg. The sex cycles of spawners from cages and cooling pond are significantly different. Silver carp reduced the number of phytoplankton, and grass carp almost completely destroyed macrophytes in the cooling pond. The population of herbivorous fish of the Amur line, living in the cooling pond of the Primorskaya power plant, is a reserve for replenishing the number of herbivorous fishes in the nearby Bikin and Ussuri rivers. The work is relevant in connection with the need to preserve, reproduce and keep clean the Amur line of herbivorous fish in Russia