FISHES

FISHES (Pisces), a superclass of vertebrate subtype. There are two classes of F.: cartilaginous and boney F. There are about 60 known orders with more than 20 thous. species. There are 50 species of Syngnathiformes, Scorpaeniformes, Siluriformes, Gadiformes, Esociformes (represented by 1 species – northern pike), Cypriniformes, Salmoniformes, Perciformes, and Acipenseriformes orders in the RB. Ectotherms. They have streamlined bodies, which are compressed laterally and covered with scales, spinules and bone plates, and in rare cases are naked. Their length varies from a few cm to 1.5 meter and more. They grow throughout their whole life, their lifespan varies from a year to 100 years and more. Juvenile fishes usually eat protea, rotifers, small crustacea, etc. Adult fish eat bottom dwelling invertebrates, and plants. Carnivore fishes eat small vertebrates. Six species are included in The Red Lists of the RB and the RF (Russian spirlin, European bullhead, sterlet, taimen, brown trout, grayling), Russian sturgeon is also included in The Red List of the RB.