Taxonomy of piscian cestodes of the genus Pseudocaryophyllaeus (Caryophyllidea- Lytocestidae) from freshwater fishes of Varanasi District (Uttar Pradesh), India

Abstract

The present morphotaxonomic study has comprised of the regional survey for piscian cestode parasites from freshwater fishes of Ganga river and its tributaries, Varanasi District (U.P.) India. This sampling expedition was conducted from October 2017 to March 2018 in the autumn-winter season in which two Caryophyllidean parasites of the genus Pseudocaryophyllaeus from host fish Clarias batrachus (Linn.1758) is described here. Under this expedition, all recovered parasitic samples and after preserved as holotype specimens of the parasites have been analyzed, specifying cladistic taxonomic descriptions and morphological characterization of rare piscian cestode (tapeworm) species. During sampling, fishes were angled and caught by traps on the spot at selected water bodies of sampling sites with the help of local fishermen and along with it, few mature freshwater fishes from the local fish market were collected. For morphological and biostatistical analysis the collected fishes were carried out to the laboratory. A total of four cestode parasites were found from the infected intestine of the host fishes. Parasites obtained from the infected host fishes were preserved in 5% formalin using labeled vials for further study as a holotype specimen. Taxonomic studies of tapeworms show that parasitic diversity can be seen at a certain seasonal period in the Ganga river and its tributaries of the Varanasi region. Morphotaxonomic differential characterization of finding species has reported as body elongated, narrow. Scolex slightly distinctly demarcated from the neck. Ovary H-shaped, situated near the posterior end of the body. Uterus present in lateral coils of the median field. Testes ovoid or spherical. Vitelline follicles cortical. Eggs ovoid, smooth and operculated. This study provides a scientific approach to understand the diversity of piscian cestode parasites of some freshwater fish species found in the river Ganges based on cladistic taxonomy.