Trichodian anabasi sp.n. (Cilioiphora: Trichodinidae) from Climbing Perch, Anabas testudineus (Bloch, 1795) (Anabantidae) in Chittagong

A population of trichodinid (Ciliophora: Trichodinidae) was found in the gills of climbing perch, Anabas testudineus (Bloch, 1795) and was described as a new species. It is characterized by large body dimensions and having uniformly stained, dark central area at the centre of the adhesive disc; broad blade with angular and slightly rounded distal margin and flat tangent point, but almost parallel anterior and posterior margin; stout and cylindrical central part with bluntly rounded point which extends slightly more than halfway to the y-axis; and the ray is slightly curved in the posterior direction with anterior margin parallel to the y+1 axis and distinct central groove. Approximately 19.6% of the host fishes (45 out of 230) were infected with the ciliate on their gills during August 1999 and December 2001, The prevalence of this ciliate was higher during the post monsoon and colder period of the year. The variation is recorded and discussed. The species is probably more closely related to Trichodina ngoma, T. kwando, T. frenata and T. mutabilis.