Thaparotrema akbari new species of genus Thaparotrema Gupta, 1955 from host Rita rita (Siluriformes: Bagridae) of River Indus Sindh Pakistan

During current study on order Siluriformes belong to diverse group of ray-finned fishes. Rita rita Siluriformes catfish collected from River Indus Jamshoro, Pakistan were bought to Parasitology laboratory of zoological department. Fishes were dissected for examined of helminth parasites. Total 12 specimens of genus Thaparotrema were collected from gallbladder of hosts and processing through standard method. Diagram were made and identify with the help of keys and literature. The new species Thaparotrema akbari identified on the basis following differential characters having large body size, elongate and narrow shape, oral sucker elongate and egg shape, ventral sucker wheel shaped, pharynx oval shape, anterior testis rounded to quadrangular in shape, posterior testis pentamerous in shape with broad anterior and narrow posterior end, ovary heart shape or triangular, seminal receptacle quadrangular tube shape and vertical in position, uterine coils almost overlapped caecum and whole middle region of body, vitelline are in small follicle.


Description
The description of specimen base on figure 1 and 2. Body of parasite elongate, narrow, curved at many regions, spindle shape measures 5.6-5.36 X 0.5-0.6, anterior region of body long and narrow, middle region long and wider, again posterior region long and narrow. Widest at post-equatorial region of body. Tegument without spines. Oral sucker small, elongate, egg shape, terminal measures 0.02-0.07 X 0.16-0.17. Ventral sucker well developed, muscular, rounded wheel shaped and pre-equatorial measures 0.26-0.29 X 0.22-0.24. Prepharynx long measures 0.18-0.18 X 0.06-0.06 and pharynx oval shape, vertical in position measures 0.04-0.05 X 0.1-0.1. Esophagus short, broad measures 0.04-0.06 X 0.08-0.09 and intestinal bifurcation near to anterior region just after the oral sucker. Caecum narrow, extended from pharynx to the ventral sucker and then overlapped by uterus. Testes two tandem, diagonal, postequatorial, anterior testis rounded to quadrangular in shape measures 0.28-0.35 X 0.26-0.31, posterior testis pentamerous in shape measures 0.36-0.36 X 0.28-0.30. Ovary heart shape or triangular, anterolateral to seminal receptacle, right side of body measures 0.16-0.19 X 0.22-0.22. Seminal receptacle pretesticular, quadrangular tube shape, vertical in position measures 0.12-0.13 X 0.32-0.37. Uterine coils well developed, almost overlapped caecum and whole middle region, uterus from anterior end of body measures 1.26-1.27 and from posterior end of body measures 1.08-1.11. Vitelline follicle laterally fields from anterior region to ovary. Genital pore anterior to ventral sucker.

Discussion
The comparative measurement of present species with previously reported species of genus Thaparotrema given in table 1 and 2. Detail morphological difference given below: Thaparotrema vittalani [1, 2, 4] collected from intestine of and gallbladder of fish Rita rita in India varies from new species by fusiform, pear shape body; widest at post equatorial region of body; tegument spined; oral sucker rounded; prepharynx absent; pharynx rounded; esophagus long; caeca extended from anterior region to posterior extremity of body, not overlapped by uterus; testes separated by excretory bladder, oval to rounded in shape; ovary rounded; laurel canal present; uterine coils not much compact, intra-caecal; vitelline follicles not much compact, extra-caecal, excretory bladder Y-shape.

Vitelline follicle
Laterally fields from anterior region of ventral sucker to ovary.
Lateral fields from ventral sucker to the seminal receptacle Extending between posterior of ventral sucker and seminal receptacle Thaparotrema shamimi [13] collected from gallbladder of Rita rita from Pakistan varies from new form by widest body of worm elongate; oral sucker rounded with curved at posterior; pharynx rounded in shape and attached to oral sucker; ventral sucker oval, large, pre-equatorial region of body; testes two diagonal, at posterior region of body, anterior testis square in shape and posterior testis triangle in shape, broad anteriorly with narrow posteriorly; ovary heart shape, vertical in position, pre-semino-receptacle left side of body; seminal receptacle oval in shape, vertical in position, pre-testicular; uterine coils highly condense, cover whole middle region of body, extended between posterior margin of ventral sucker to ovary; seminal vesicle oval in shape, at lateral side of ventral sucker.

Conclusion
The present trematodes belong to genus Thaparotrema on the basis of following differential characteristics including body shape and width, tegument without spines, suckers shape and position, prepharynx long and pharynx oval shape, testes shape and size, ovary heart shape, seminal receptacle shape and position, vitelline are in the form of small follicles and identified as new species Thaparotrema akbari.