A New Species of Asymphylodora (Trematoda: Lissorchiidae) from Bata, Labeo bata (Cyprinidae), in the Sharda Canal of India, and Amendment of the Diagnosis for Asymphylodora

A new species of Asymphylodora (Trematoda: Lissorchiidae) is described from the intestine of a bata (Labeo bata) collected from the Sharda Canal in Biswan (Sitapur), state of Uttar Pradesh, India. This is the fifth species of Asymphylodora named in India and the largest specimens reported from India (other than Asymphylodora indica, Asymphylodora kedarai, Asymphylodora ritai, and Asymphylodora punctatusi). It is also the second largest known in the genus next to Asymphylodora atherinopsidis. Members of the new species are similar to A. kedarai and A. punctatusi in that they possess the genital pore and cirrus on the right side of body rather than left as in the other species in world. In the new species the prepharynx is well developed, the esophagus is longer, the ceca extend posterior to the end of the testis, the size of testis is much larger, the vitellaria extend to near the anterior end of the ovary, there are both a spiny cirrus and a metraterm, and the body is longer than in both A. kedarai and A. punctatusi. Moreover, specimens of new species possess an ovary overlapping the anterodorsal margin of the testis rather than a pretesticular ovary as in A. punctatusi, and the sucker width ratio differs (1:0.90 in the newly described species versus 1:0.84 in A. punctatusi). The newly described species can be distinguished from A. kedarai by the presence of an undivided unipartite seminal vesicle and in relation to sucker width ratio (1:1.55 in A. kedarai). This is the first report of a species in the genus Asymphylodora from L. bata. Diagnosis for the genus is amended.