628 



BIOLOGY OF THE SEAS OF THE U.S.S.R. 

 Table 269 



Species 



Percentage dry weight 

 Proteins Fat Ash 



Caspian 

 Chironomids 

 Oligochaetes 



Mediterranean 

 Nereis 



6612 

 63-70 



66-88 



7-60 

 5 00 



7-73 



10-40 

 5-85 



13-82 



mullet, flatfish and mosquito-fish, were introduced into the Caspian Sea fauna 

 by man. Of the 38 aboriginal genera of the Caspian fish, eleven — Caspiomy- 

 zon, Caspialosa, Neogobius, Mesogobius, Proterorhinus, Asra, Caspiosoma, 

 Hyrcanogobius, Benthophiloides, Benthophilus and Anatirostrum — are en- 

 demic forms of the Pontic-Caspian-Aral region ; of these Caspiomyzon, Asra, 

 Anatirostrum and 22 other species exist only in the Caspian Sea. The greatest 

 variety of species is given by the Gobiidae, Cyprinidae, Clupeidae and Aci- 

 penseridae families. The Clupeidae and Gobiidae families are exceptional in 

 their process of forming small taxonomic units. For example, Caspialosa 

 caspia has five forms and Caspialosa brashnikovi has seven forms (sub- 

 species). 



Table 270. Composition of Caspian Sea ichthyofauna 



