BIHANG TILL K. SV. VET.-AKAD. HANDL. BAND 26. AFD. IV. N:0 8. 7 



a higher degree than the others and St. marinum is the most 

 advanced form with larger jaws (preying on larger fishes) 

 and plumper in ali dimensions. The Volga-pikeperch does 

 not ever attain the same great size as the common pikeperch, 

 the former not weighing more than 3 funt or about P/2 kilo. 

 But the common pikeperch attains a weight of more than 

 eight to ten times that. 



In his great work on the »Scandinavian Fishes» Smitt 

 seems to regard it as donbtfiil whether Sti^ostedium volyense 

 can be regarded as a valid species. From the above written 

 account may, however, be seen that it really is so. The 

 Russian fishermen distinguish all three forms with separate 

 names, calling S. Iitcioperca »sudok» or >^sudak», S. volgense 

 »bersch» and S. marinum »tschornij bersch», that is »black 

 bersch». The two first raentioned ones are canght in immense 

 quantities in the river Volga. The »sudok» lives also in the 

 Caspian Sea. I saw it, for instance, caught at the open sea- 

 shore in the neighbourhood of Petrovsk and at Baku, and 

 was informed that it was also caught at the Persian coast. 

 It seems consequently to be distributed all över the Caspian 

 Sea but enters the rivers for spawning. Its habits of re- 

 gularly visiting the sea depart from those of our Scandina- 

 navian pikeperch which is a rather rare fish at the Baltic 

 coasts and is only found in the inner archipelago. The habits 

 of the pikeperch and of the perch are accordingly contrast- 

 ing in the two regions. When I left the Volga delta the 

 first days of May the pikeperch was not yet quite ready for 

 spawning. — The »bersch» is more of a fresh water fish than 

 the »sudok». In his book on the fisheries of the Caspian Sea 

 and Volga Grimm does not count the »bersch» among the sea- 

 fishes (conf. 1. c. p. 67). I was, however, informed that it 

 was caught in the sea near Baku by seining, although not in 

 great numbers. Kessler seems to make a similar statement.^ 

 The »tschornij bersch» is a rare fish I obtained but one 

 specimen which was caught in the sea at Petrovsk. This 

 part of the sea seems to be its regular haunts and I also 

 beard it called »Petrovsk sudok» by an old fisherman who 

 believed that it entered the river Terek for spawning. This 

 is however uncertain. 



1 Fishes of Aral-Caspian and Black Sea (Russian). Petersburg 1877, p. 202. 



