One known and an unknown species of the genus Thaparocleidus Jain, 1952, infecting Sperata aor (Hamilton, 1822): comparison with species from China, on molecular basis

Sperata aor commonly called as long- whiskered cat fish or “Bada Tengan” in local fish markets harboured one new and one previously known species of genus Thaparocleidus Jain, 1952, along with two species of Cornudiscoides Kulkarni, 1969, infesting gills. Thaparocleidus aori (Rizvi, 1971) Lim, 1996, was earlier described by Rizvi therefore was briefly recorded in the present study, except the egg. The newly found species Thaparocleidus susanae n.sp was characterized by the structure of its peculiar copulatory organ. Phylogenetic relationship of the two species under study, along with 14, reterived from GenBank was established using the sequences of 28S rDNA region (Dactylogyrus Diesing, 1850 taken as an out group).

made with the help of an image taken with camera (Olympus-Photometrics coolsnap) attached with microscope, using Image-ProExpress 6.0 (for image analysis).

Molecular analysis DNA isolation
Single parasite was collected in absolute ethanol for DNA extraction. Total DNA was extracted from the collected parasite using Qiagen's Dneasy Blood and Tissue Kit (Cat. No. 69504) by following protocol as per DNA extraction kit with slight modifications.

Data analysis
Sequencing products were subjected to BLAST (Basic Local Alignment Search Tool) for homology search. Multiple sequence alignment was performed using Clastal W [5]. The sequence of query species (T. susanae n. sp. and T. aori) was compared with retrieved sequences

Remarks
This species was characterized by structure of copulatory complex having a pointed "angle" shaped accessory piece, attached distaly to a copulatory tube with three clockwise coiles and long vaginal tube having a funnel like, lightly sclerotised opening. The present species resemblse with T. mystusi in comparative morphology of vaginal apparatus, dorsal anchors, dorsal bar and hooks but differs in the structure of copulatory complex, copulatory tube without coiling and accessory piece being pitcher shaped, also the ventral bar is longer, its middle region being fine and thin in T. mystusi which was smaller and of same width throughtout its length in T. susanae n. sp. Similarly, the ventral anchor has a sharp and pointed inner root end in T. mystusi while in T. susanae n. sp the two roots are short, pointed and of almost smiliar length. It also resembles with T. speratai in comparative morphology of vaginal apparatus, ventral bar and hooks but chiefly differs in the structure of copulatory complex which had single, horse shoe shaped accessery piece attached diataly to copulatory tube. It also differs from T. aori in the structure of copulatory complex, vaginal armature, ventral anchors, ventral bar, dorsal bar and dorsal anchor. Therefore this species, regarded as a new species, named in honour of Prof. L. H. S. Lim, for her outstanding contributions.

Discussion:
In monogenes sequences of ribosomal subunits were widely used to infer phylogenetic relationships at the level of families and sub families [10-12] and also to investigate evolutionary association between the parasites and their hosts [12,13].
In the present study, phylogenetic analysis using 28S genes showed a well resolved grouping of two Indian species of the genus Thaparocleidus under study and 14 from China. In