THE BLACK SEA 



437 



shores of the Crimea (1949), within the zone of distribution of marine organ- 

 isms above sea-level, also distinguishes two separate zones of amphibiotic 

 life — the supralittoral and pseudolittoral. In his view the first 'corresponds 

 completely to the supralittoral of the open seas, the second — the overwash 

 zone or pseudolittoral — is analogous to the true littoral . . . the pseudolittoral, 

 like the true littoral, is subject to periodic drainage and flooding, since it is 





Fig. 209. General picture of distribution of Black Sea bottom fauna (Zernov's data 

 slightly altered). 1 Crab Pachygrapsus ; 2 Barnacle Balanus; 3 Mollusc Patella; 

 4 Brown alga Cystoseira; 5 Green alga Ulva and Enteromorpha ; 6 Sea mussel 

 (Mytilus); 7 Actinia; 8 Sea-urchin; 9 Nemertines Lineus; 10 Lower worms Sac- 

 cocirrus; 11 Amphipoda (scuds); 12 Mollusc Venus; 13 Red mullet; 14 Flat fish 

 Rhombus; 15 Crab-hermet Diogenes; 16 Zostera; 17 Pipe fish; 18 Crenilabrus; 

 19 Sea-horse; 20 Shrimp Leander; 21 Oysters; 22 Sea-robin Pecten; 23 Mussel; 

 24 Red Porifera Phyllophora; 25 Red Porifera Suberites; 26 Ascidian Ciona; 

 27 Phaseolin mollusc (Modiola phaseolina) ; 28 Brittle star Amphiura ; 29 Mollusc 

 Throphonopsis ; 30 Medusa Pilema pulmo; 31 Ctenophora Pleurobrachia ; Hydrogen 



sulphide. 



situated within the limits of the fluctuation of deep-water waves'. In Mokiev- 

 sky's opinion the supralittoral lies above the limit of overwash, and the water 

 impregnating it enters the beach owing to its capillarity. 



The bivalves Donacilla cornea and the polychaete Ophelia bicornia (Oph. 

 taurica ?) are the mass forms of the pseudolittoral of the Crimean coast. 

 In some cases Donacilla gives a biomass of up to 689 g/m 2 and 3, 100 specimens 

 per m 2 , and Ophelia yields 394 g/m 2 and 400 specimens per m 2 . Apart from 

 these two dominant forms the following are fairly common : the amphipod 

 Pontogammarus maeoticus, with a maximum biomass of 83 g/m 2 and greatest 

 number of specimens of 1 1,800 per m 2 ; Mytilus mysid, Gastrosaccus sanctus, 

 the isopod Euridice pulchra, and the polychaetes (Spionidae) Nerine cirratus 

 and Nerinides cantabra. Sphaeroma serratum and Idothea baltica are much 



