From the publisher. [ The Caspian Sea is one of the most important fishery reservoirs of the USSR. This is the world's largest lake with salt water separated from the rest of the seas in the post-glacial period and preserved the richest late-tertiary saltwater fauna of marine origin, formed in isolated tertiary, South Russian waters with many changes in salinity .......... The isolated position and low salinity of the Caspian Sea prevented the settlement of many animals in this body of water, including predatory forms (sharks, stingrays, sea stars, large predatory mollusks, actiniums, large jellyfish) and weed species (large sponges, most hydroids, moshanoks)........ All known species of free-living invertebrates from the Caspian Sea are included in this determinant as far as possible.......... Scan provided by A. Shipunov .