. Biology of the seas of the Marine biology -- Soviet Union; Hydrology -- Soviet Union. 662 BIOLOGY OF THE SEAS OF THE Fish-parasites. Seventy-one species of different fish-parasites should be added to this list. According to V. Dogjel and B. Bykhovsky (1934) they are distri- buted among the following groups: Protozoa Coelenterata Trematoda Cestoda Nematoda Hirudinea Crustacea 14 species 1 species 30 species 9 species 10 species 2 species 5 species. Fig. 313. Zonal distribution of Aral fauna (Zenkevitch, 1951). For the Sea itself only 33 species of parasites have been confirm
. Biology of the seas of the Marine biology -- Soviet Union; Hydrology -- Soviet Union. 662 BIOLOGY OF THE SEAS OF THE Fish-parasites. Seventy-one species of different fish-parasites should be added to this list. According to V. Dogjel and B. Bykhovsky (1934) they are distri- buted among the following groups: Protozoa Coelenterata Trematoda Cestoda Nematoda Hirudinea Crustacea 14 species 1 species 30 species 9 species 10 species 2 species 5 species. Fig. 313. Zonal distribution of Aral fauna (Zenkevitch, 1951). For the Sea itself only 33 species of parasites have been confirmed. All the others are inhabitants of low-salinity areas. Among these parasites the Coelenterata Poly podium hydriforme and the Trematoda Nitschia sturionis, brought into the Aral Sea with starred sturgeon during its acclimatization, are of great interest.* About a hundred specimens of starred sturgeon were introduced into the Aral Sea from the Caspian Sea, without being dis- infected against parasites. The parasite of the gills of the starred sturgeon is the trematode Nitschia, which is widely dispersed in the Caspian Sea and does little harm there. No more than 40 specimens per fish have been recorded in that Sea. Once in the Aral Sea, however, the trematode transferred to the local sturgeon Acipenser and caused a serious epizootic epidemic which led to high mortality among fish. Up to 600 trematodes have been counted on one sturgeon Acipenser. Over a period of some years the number of Trematoda dropped sharply; * There is, however, an opinion that Nitschia sturionis existed in the Aral Sea before the starred sturgeon was Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Zenkevich, L. A. (Lev Aleksandrovich), 1889-1970. New York, Interscience Publishers
Size: 2132px × 1172px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionbiodiversity, bookleafnumber666
