The Morphology and Biology of the Trematode Gigantobilharzia Acotylea (Digenea, Schistosomatidae)
Morpho-biological traits of the trematode Gigantobilharzia acotylea Odhner, 1910 at all stages of ontogeny are studied. Mollusks Physa fontinalis and Anisus spirorbis widespread in the waterbodies of the Syrdarya River valley were found to be intermediate hosts of this trematode under natural and experimental conditions in Uzbekistan. Prevalence of infection of P. fontinalis and A. spirorbis by Gigantobilharzia spp. parthenitae and cercariae reached 0.4 and 0.3%, respectively. Experimentally, 100% of these mollusks were infected. The maturation of cercariae in intermediate hosts ranged from 23 to 44 days depending on temperature. The cercariae actively penetrated the skin of birds and reached maturity in 30-35 days. A complex of traits of various developmental stages, particularly cercariae necessary for the differentiation of the Gigantobilharzia spp. is suggested based on of the analysis of morpho-biological peculiarities of these trematodes.
Study of Biology, Morphology and Taxonomy of the Nematode Stephanofilaria assamensis (Filariina, Stephanofilariidae). Saparov K. A., Akramova F. D., Azimov D. A., Golovanov V. I. — Biological characters of Stephanofilaria assamensis Pande, 1936, a parasite of cattle, were studied under environmental conditions of Uzbekistan with the emphasis on morphology of all developmental stages. Bloodsucking flies Haematobia atripalpis Bezzi, 1895, Lyperosia titillans Bezzi, 1907 and L.irritans Linnaeus, 1758 were established as intermediate hosts. Prevalence of the nematode larvae in the flies constituted 2.1, 1.5, and 1.2 %, respectively. Characters for the species identification were revised. On that basis S. zaheeri Singh, 1958 is regarded as a synonym of S. assamensis. The place of Stephanofilaria genus in the system of Stephanofilariidae is discussed.
Fauna and distribution patterns of the endohelminths of Cypriniformes from water bodies of the mid-course of the Syrdarya River were investigated. Forty-nine endohelminth species were recorded from Cypriniformes in this region, including 18 species of trematodes, 13 species of cestodes, 14 species of nematodes and 4 species of acanthocephalans. Twenty-nine species are first reported from this region. Original data on the composition and structure of endohelminth communities are given.
The paper presents results of the studies on alterations in the structure and functions of mollusc organs under the effect of the trematode Orientobilharzia turkestanica (Skrjabin, 1913) larvae. Destructive changes were observed along with a vast necrosis of the hepatopancreatic gland. Parasitism of O. turkestanica parthenitae and cercariae in L. auricularia causes deep histopathological changes in the tissues. Protein, carbohydrate and fat metabolism disorders result in the weakening of molluscs and loss of their lability, which is essential for adaptation to environmental changes. The latter is confirmed by a high mortality of infected individuals.