Trichodina shitalakshyae sp. n. and Trichodina acuta Lom, 1961 (Ciliophora: Trichodinidae) from the freshwater fishes in the Shitalakshya River, Bangladesh.

Abstract

Two trichodinid species were identified from freshwater fishes, Mystus bleekeri and Glossogobius giuris, in the Shitalakshya River of Gazipur district, Bangladesh. Trichodina acuta Lom, 1961 is found for the first time in Bangladesh. Trichodina shitalakshyae sp. n. is characterized by having an undivided clear central area in the adhesive disc with a rounded or slightly undulated perimeter containing a few dark granules which form patches; elongated and rectangular blade with large interblade space and blunt tangent point; indistinct anterior blade apophysis and a shallow apex at the base of blade that never extends beyond the Y+1 axis; moderately wide and triangular central part with blunt point; and space between tip of ray and central clear area forms a wide impregnated ring. Based on these characters and the unique shape and absence of variability of the denticles among the silver impregnated specimens of the present species, it resembles Trichodina porocephalusi Asmat, 2001.