ВСПЫШКА ЧИСЛЕННОСТИ МЕДУЗЫ AURELIA AURITA (L.) В ЧЕРНОМ МОРЕ | An increase in the number of Aurelia aurita (L.) in the Black Sea
1984
Зайцев, Ю. П. | Полищук, Л. Н.
In recent years the number of jelly-fish in the Black Sea has markedly increased. Its biomass in the summer-autumn-winter period of 1980-1981 amounted to 222·106 t of wet or 295·104 t of dry weight. The vital space of one specimen became 60 times as small as in 1949-1962. This resulted in an increased influence of jellyfish on plankton. Vertical and horizontal distribution of jellyfish is not uniform. Daily vertical migrations are not always clearly expressed. No distinct dependence is revealed between vertical distribution of jellyfish and the sea water temperature. There is a direct relationship between the density of jellyfish and the amount of zooplankton. The outbreak in the jellyfish number may be due to a decrease in the stock of plankton-eating fish as well as to the anthropogenic factor. Specimens differing in symmetry from normal four-rayed one are found. They account for 2.75 %.
显示更多 [+] 显示较少 [-]Приводятся сведения о современном состоянии запасов медузы в летне-осенне-зимний период 1980—1981 гг. в Черном море, вертикальном и горизонтальном распределении ее численности и биомассы, обнаружении особей с симметрией, отличающейся от нормальной четырехлучевой. Высказываются соображения об изменившемся влиянии медузы на биоту водоема и делаются попытки объяснения вспышки ее численности.
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