Population Status of the Ctenophores <i>Mnemiopsis leidyi</i> Agassiz, 1865 and <i>Beroe ovata</i> Bruguiere, 1789 in the Waters of the North and Middle Caspian Western Shelf in August–September, 2022

Abstract

The latitudinal distribution of the ctenophores Mnemiopsis leidyi A. Agassiz, 1865 and Beroe ovata Bruguière, 1789 in the Russian sector of the Caspian Sea has different borders of their ranges. Studies on the occurrence of ctenophores in the water column have demonstrated that each species has a characteristic temperature limit of its vertical distribution. Investigations into interactions between ctenophores showed a considerable abundance suppression of M. leidyi (particularly of smaller individuals) by B. ovata.