Parapharyngodon hemidactylii Gupta, Bhaskar & Gupta, 2009, n. sp.

Parapharyngodon hemidactylii n. sp.

(n= 15 males, n= 20 females)

The parasite is a tender white cylindrical worm tapering at both the ends. Prominent annulations visible beginning just behind cephalic extremity and continuing up to the anus. Sexual dimorphism is clearly distinct. Triangular oral opening is surrounded by 3 bilobed lips.

Adult male (All measurements are in mm. unless otherwise stated). Cylindrical worm 0.755 (0.47–0.96) long, 0.236 (0.18–0.37) wide at its maximum width (Plate I Fig. 1; Plate III Fig. 1). Cuticle with annulations forming swollen rings in posterior region. Esophageal tube 0.283 (0.20–0.54) long and 0.031 (0.02–0.04) wide. Esophageal bulb 0.079 (0.05–0.11) long and 0.089 (0.07–0.11) wide (Plate I Fig. 2). Nerve ring not clearly distinct. Caudal papillae absent. Spicules 0.049 (0.035–0.085) long and pointed (Plate I Fig. 3). Tail filament 0.065 (0.01–0.09) long, terminal in position and directed posteriorly (Plate I Fig. 4, 5; Plate III Fig. 2).

Adult female (All measurements are in mm. unless otherwise stated). Body length 3.47 (2.47–4.05), width 0.405 (0.33–0.51) at maximum width (Plate II Fig. 1, 2; Plate III Fig. 3). Cuticle with annulations approximately 0.032 (0.01–0.055) long and 0.021 (0.015–0.035) in width (Plate II Fig. 1; Plate III Fig. 4). Esophageal tube or corpus 0.55 (0.50–0.64) in length and 0.05 (0.045–0.06) in width and esophageal bulb 0.194(0.17–0.215) in length and 0.225(0.21–0.26) in width (Plate II Fig. 2; Plate III Fig. 5). Reproductive structures confined to body cavity between vulva and anus and the developing ova visible in the uterus (Plate III Fig. 6). Nerve ring not clearly distinct. Excretory pore and vulva situated at 1.18 and 1.44 (1.20–1.70) respectively from the anterior end (Plate II Fig. 3; Plate IV Fig. 1). Body with conical termination (Plate II Fig. 5; Plate IV Fig. 2). Tail 0.11 (0.075–0.135) long and 0.063 (0.045–0.10) wide (Plate IV Fig. 3). Eggs oval 0.08 (0.02–0.10) long, 0.041 (0.01–0.06) wide (Plate II Fig. 4, 6; Plate IV Fig. 4)

PLATE I Camera lucida diagrams of Thelandros hemidactylii n. sp. Male showing Fig. 1 Anterior most region; Fig. 2 Anterior region; Fig. 3 Spicule; Fig. 4 Posterior region (dorsoventral view); Fig. 5 Posterior region (lateral view).

PLATE II Camera lucida diagrams of Thelandros hemidactylii n. sp. Female showing Fig. 1 Anterior most region; Fig. 2 Anterior region with oesophagus and intestine; Fig. 3 Vulva region; Fig. 4 Egg; Fig. 5 Posterior region; Fig. 6 Middle region with eggs.

PLATE III Photomicrographs of Thelandros hemidactylii n. sp. (X400). Male showing Fig. 1 Anterior end; Fig. 2 Posterior end; female Fig. 3 Anterior end showing oesophageal region; Fig. 4 Surface of Thelandros showing cuticular annulations; Fig. 5 Oesophageal bulb and intestinal junction; Fig. 6 Intestinal region showing developing ova.

PLATE IV Photomicrographs of Thelandros hemidactylii n. sp. (Fig. 1– 3 X400). Female showing Fig. 1 Parasite showing vulva region; Fig. 2 Parasite showing posterior end with eggs; Fig. 3 Parasite showing tail region; Fig. 4 Parasite showing eggs (X1000).