522 



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



cases anchovy stomachs were filled with polychaetes and small Hydrobia 

 only. 



Copepoda form the main food of anchovy and Atherina and even more so 

 of Clupeonella (Fig. 248). The intestines of these three fish contain on the 

 average 60 to 70 per cent by weight of copepods (85-8 per cent in Clupeonella, 



ADULT 



APRIL-MAY JUNE 



YOUNG 



JULY 



AUGUST 



JUNE 



SEPTEMBER OCTOBER NOVEMBER 



[HUPhytoplankton 

 ISSS Rotatoria 

 dZlPolychaeta larvae 

 ESPolychaeta 

 DUCIadocera 

 ■■Copepoda 

 '""ICirripedia larvae 

 HillMysidacea 

 SEPTEMBER OCTOBER :23Mollusca larvae 

 5SZ! Hydrobia 

 ^H3Fish larvae 



ANCHOVY 



SEA OF AZOV 



MARCH APRIL- 

 MAY 



BAY OF TAGANROG 



AUGUST 



SEPTEMBER 



APRIL-MAY 



AUGUST 



CLUPEONELLA 



SEPTEMBER OCTOBER NOVEMBER DECEMBER 

 [■]•'] Phytoplankton 

 Щ Rotatoria 

 pq Polychaeta larvae 

 Ol Cladocera 

 IB Copepoda 

 рт] Cirripedia larvae 

 E3 Mysidacea 

 E*3 Amphipoda 

 LD Mollusca larvae 

 ШИ Fish larvae 



SEPTEMBER 



Fig. 248. Food spectra of (A) anchovy and (B) Clupeonella in the Sea of Azov and 

 their changes during the year. The area of the circle corresponds to the value of the 

 repletion index. White sector within the circle is the percentage of empty stomachs 



(Okul, 1941). 



40 per cent in anchovy, 56-5 per cent in Atherina). For herring, however, 

 Copepoda are not an important item of diet. 



In spring Rotifera constitute a large part of the food of fish, ranging from 

 25 to 63 per cent for Clupeonella and up to 21 per cent for anchovy. For 

 a short period in June (at the time of their mass occurrence) Cirripedia larvae 

 may acquire an important place in the nutrition of plankton-eating fish; 

 anchovy food includes 33 to 37 per cent of them, that of Clupeonella 25 per 

 cent, of Atherina 10 to 14 per cent and of herring 4 per cent. In spring and 

 autumn Mysidacea (mainly Macropsis slabberi) plays an important role in 

 the nutrition of Atherina and herring, forming 31 to 47 per cent and 21 per 

 cent of the whole content of stomachs of herring and Atherina respectively. 

 Mollusc larvae have little feeding value for fish (1 to 4 per cent). Herring eat 

 large numbers of fish fry and young fish. 



