Study on the Trichodinid Ectoparasites (Ciliophora: Trichodinidae) in Cirrhinus reba (Hamilton, 1822) Collected from the Kaptai Reservoir, Bangladesh

Abstract

A study was conducted on Cirrhinus reba (Hamilton, 1822), family: Cyprinidae, collected from the Kaptai Reservoir to investigate ecto-parasites. During this study, a novel record of an ecto-parasitic trichodinid ciliate (protozoan parasite) of the genus Trichodina (Ehrenberg, 1838) has been detected from the gills of Cirrhinus reba (Hamilton, 1822). Investigations were carried out between October 2021 and September 2022 at eight designated stations. A total of 108 host fish were examined, of which 17 individuals (15.74%) were found to be infected, indicating a low to moderate prevalence of infestation. Specimens were prepared using dry silver impregnation method, and the morphological and morphometric features of the adhesive disc and denticles were studied in detail. The denticle structure, including blade, ray, and central part, confirmed its identity with Trichodina heterospina originally described from Sardinella fimbriata in India.  This study represents the first record of T. heterospina from C. reba in Bangladesh, extending the known host and geographical distribution of the species. These findings contribute valuable baseline data on the diversity of trichodinid ciliates in freshwater ecosystems of Bangladesh and highlight their potential significance in fish health and aquaculture management.

Chittagong Univ. J. B. Sci. Vol. 13 (1&2): 40-45, 2025