New record of gill hemorrhagic parasite Myxobolus richardsonii n. sp. (Cnidaria: Myxozoa) infecting Schizothorax richardsonii in Kashmir Himalayas

AbstractMyxozoans are highly specialized metazoan parasites with a very diverse host range that live on aquatic hosts. In both wild and farm-raised fish, myxozoans are the most frequent parasites.  The aim of the current study was to evaluate any myxozoan parasite found in different organs ofSchizothorax richardsonii.  Live fish were transported with artificial aeration to the University of Kashmir. Thirty-five fish specimens were examined during the study period, and only gills of 6 fish were determined to be infected. Taxonomic study was carried out with the help of different keys, and histopathologcal study w as assayed in order to study the diseased organs of the fish. Besides, characterization of partial 18S rDNA gene was also done in the present study as per the standard procedures. The findings showed that the plasmodia were big, oval shaped, and white in color, measuring 1.5 × 2.0 mm. They we re referred to as intralamellar vascular-type plasmodia (LV3). Histological changes in the gills included inflammation, gill epithelium lifting, hypertrophy of lamellar cells, and fusion of nearby gill lamellae. The myxospore body had a tiny ICP at the anterior end and was spherical to ovoidal in form, measuring 11.19  × 7.66 µm. Polar tubules were pyriform in shape and measuring 6.12 × 1.95 µm, having coils up to 7 in number. The gill plasmodium index showed a moderate level of infection (GPI 2). According to their phylogenetic relationships,M. richardsoni...
Source: Comparative Clinical Pathology - Category: Pathology Source Type: research