Bioscience Discovery, 4(2):245-249, July 2013 ISSN: 2229-3469 (Print) On a New Species of Rhabdochona, Cyprinus carpio (L.) in Jaikwadi Dam of Aurangabad (M. S.) India Nimbalkar R K, R V Deolalikar and V N Kamtikar Department of Zoology, Vinayakrao Patil College, Vaijapur, Dist Aurangabad (M.S.) India [email protected] ABSTRACT A new nematode species, Rhabdochona carpiae sp. n. (Nematoda: Rhabdochonidae), is described from the intestine of the freshwater common carp Cyprinus carpio (Linnaeus, 1758) at Jaikwadi dam of Aurangabad district. The species is differs from other representatives of the subgenus Globochona Moravec, 1972 which possess eggs provided with swellings in having a spinose formation at tip of tail, in male and female. The body length of female (9.2-25.4 mm), presence of two-three swellings on the egg, eight anterior prostomal teeth, length ratio of spicules (1:5.3.2-6.8) and arrangement of male genital papillae. This is the second species of the subgenus Globochona reported from fishes in India. Key words: freshwater fish, nematode, Jaikwadi dam, India. INTRODUCTION Genus Rhabdochona was erected by Railliet based on both male and female specimens from a in 1916 with Rhabdochona denudata from Cyprinus fresh water fish common carp Cyprinus carpio from euritharophthalmus as the type species. The genus Jaikwadi dam of Aurangabad District Maharashtra Rhabdochona includes large number of species all State of India. over the world. Yamaguti (1961) listed about 30 species under the genus Rhabdochona, Ralliet, MATERIALS AND METHODS 1916 from different hosts from various parts of the Fish were collected by a local fisherman world. Sahay (1971) revised the genus using nets from Jaikwadi dam of Aurangabad district Rhabdochona with a key to the Indian species. (M.S.) India. Twenty specimens of Cyprinus carpio Moravec (1972, 1975, 1978) extensively studied (total body length 20-30 [mean 25] cm, weight 80- the genus Rhabdochona. Sood (1988) provided key 90 [mean 85] g) specimens were dissected laterally to the species of Rhabdochona, in South Asia, In from anus to head; entire digestive tract was India Rhabdochona labeonis was describe by removed and placed in Petri-dish containing Kalyankar (1972), Rhabdochona marina was physiological saline. The internal organs were reported from the intestine of Pempheris opened lengthwise and each parasite was isolated vanicolensis (Cuvier) of Visakhapatnam (Lakshmi carefully. 18 nematodes (10 females and 8 males) and Sudha, 1999). Rhabdochona indina was were recovered from 15 fishes, maximum number reported from intestine of Pempheris vanicolensis of parasites were 1-2 in a fish. Parasites were fixed (Lakshmi, 2001) Reports also described from in 70% alcohol and glycerol (1:1). To expose key freshwater fishes Barilius vagra and Mystus anatomical features and outer integument of vitattus in Pakistan (Gjhazi et al., 2003 and Rafique nematodes, lactophenol was used. Parasites were et al., 2002). Rhabdochona sp. are reported from mounted between slide glass and cover glass using Arizona (Choudhry et al., 2004), Thailand 2 to 3 drops of glycerol. Nail polish was pasted (Boonchot and Wongsawad, 2005) and around the sides of cover slips to hold them firmly. Rhabdochona kharani was reported from Labeo For light microscopy (LM) examination, the gedrosicus in Pakistan (Kakar et al., 2006). nematodes were cleared with glycerin. Line Recently, Moravec and Kamchoo (2012) reported drawings were made with the help of Camera Rhabdochona rasborae from Rasbora paviana Lucida all measurements are in micrometres unless tirant in southern Thailand. Present description is otherwise indicated. http://biosciencediscovery.com 245 ISSN: 2231-024X (Online) Nimbalkar et al., The name of fishes was followed by Fish RESULTS AND DISCUSSION Base (Froese and Pauly 2012). Specimens were Rhabdochona carpiae sp. n. (Figure) deposited in the Helminthology section in Description: Medium-sized nematodes with finely Department of Zoology, Vinayakrao Patil College transversely striated cuticle. Oral aperture Vaijapur, Aurangabad (M.S.) hexagonal to oval, with four submedian sublabia, surrounded by four small submedian cephalic Taxonomoic summary papillae and pair of lateral amphids. Prostom barrel- Site of infection: intestine. shaped, with distinct basal teeth (Fig. F). Anterior Type locality: Jaikwadi dam, Aurangabad district of margin of prostom armed internally with sixteen Maharashtra State of India. Dam is built on River large, forwardly directed teeth (4 dorsal, 4 ventral Godavari. and 4 on each side). Vestibule long. Deirids small, GPS Co-ordinate: 19°29′8.7″N and 75°22′12″E bifurcate, glandular oesophagus 8-15-times longer (Garmin Hand Held) than muscular oesophagus. Tail of both sexes Intensity of infection: 75% (15 fish infected/20 fish conical with truncated tip. examined); 1.2 nematodes/fish Length of body 5-6. (5) mm, maximum Deposition of type specimens: Department of width 70-80 (75). Prostom 12-16 (16) long and 12- Zoology, Vinayakrao Patil College, Vaijapur Disrtict 16 (16) wide in lateral view. anterior margin of Aurangabad (M.S.) India (Cat No. Helminth 309) prostom armed internally with 16 small, forwardly Etymology: The species name Rhabdochona directed teeth (4 dorsal, 4 ventral and 4 on each carpiae (genitive) relates to the generic name side) Length of vestibule including prostom 112- of the host fish species (Cyprinus carpio Linnaeus, 122 (118). 1758). Figure Rhabdochona carpiae sp. n. A – Anterior part of male showing prostome, mesostome, cervical papillae, esophagus,( Lateral view) B - anterior end of female, showing prostome, mesostome, esophagus (Lateral view) C- tail of female showing anal opening and tail (Lateral view), D- female containing eggs, E- posterior part of male showing spicules (Lateral view), caudal papillae, cloaca and tail. F- apical view. Male (Based on eight specimens) http://biosciencediscovery.com 246 ISSN: 2231-024X (Online) Bioscience Discovery, 4(2):245-249, July 2013 ISSN: 2229-3469 (Print) Glandular oesophagus 1.60-2.04 (1.80) mm Rhabdochona singhi (Ali, 1956) from Glossogobius long, maximum width 45-58 (52); length ratio of giuris (Hamilton). Report of Kumchoo (2000), both parts 1:10-15 (1:13). Muscular oesophagus Wongsawad et al. (2004) and Boonchot and 140-220 (185) long, maximum width 12-20 (16); Wongsawad (2005) indicated that Rhabdochona Length of vestibule with prostom and entire spp. is common parasites of fishes in Thailand. oesophagus forms 35-45 (40) % of body length. Rhabdochona with 10-14 or 16 anterior teeth, tail Nerve ring encircling muscular oesophagus 160-180 tip of female conical, ending in sharp cuticular (170) from anterior extremity; excretory pore at spike or rounded; egg with smooth surface, or with 220-250 (235). Deirids not located. Preanal very fine, irregular gelatinous flocks, filaments or papillae: 7-9 (8) subventral and 1 (1) lateral pairs; special polar swelling. latter situated at about level of, or somewhat Recently described species of posterior to, third pair of subventrals. Rhabdochona exhibit some unique or rare Female (Based on ten specimens) morphological features within this genus, such as Length of body 12-26 (18) mm, maximum the shape of deirids in Rhabdochona pseudomysti width 115-280 (192). Prostom 18-23 (23) [10-16] or caudal structures in Rhabdochona rasborae and long and 14-20 (16) wide. Length of vestibule Rhabdochona thaiensis a remarkable feature of including prostom 120-160 (140). Muscular Rhabdochona (G.) rasborae is the structure of the oesophagus 170-190 (180) long, maximum width male ventral precloacal ornamentation (area 25-30 (30); glandular oesophagus 2.16-2.88 (2.40) rugosa). as mentioned by Moravec et al. (2012), in mm, maximum width 60-75 (70) length ratio of some Rhabdochona species this male ventral both parts 1:12-16 (1:14) [1:10-12]. Length of cuticular ornamentation is formed, similarly to vestibule with prostom and entire oesophagus some cystidicolids, by several longitudinal ridges or forms 12-30 (24) [25-40] % of body length. Nerve is completely missing; in Rhabdochona carpiae sp. ring, excretory pore and deirids at 165-215 (215), n. the area rugosa is missing and in Rhabdochona 215-290 (260) and 57-117 mm respectively, from rasborae (Moravec and Kamchoo, 2012) it is anterior extremity. Vulva post-equatorial, 4.70- represented by many cuticular transverse bands 12.20 (8.45) mm from anterior extremity, at 50-65 bearing numerous short longitudinal ridges. This (60) [60-62] % of body length. Vagina directed first cuticular transverse bands has been reported only anteriorly and then posteriorly from vulva. Based for the recently described species Rhabdochona on the morphological characters, anterior (G.) kurdistanensis (Moravec et al., 2012) from prostomal teeth (16 in number) and the presence cyprinid fish in Iraq. of caudal projections on the tip of the tail, present In Rhabdochona carpiae sp. n. numerous nematodes assigned to the Rhabdochona subgenus small cuticular outgrowths at the tail tip of both Globochona, as re-described by Moravec (1975). sexes are present this characteristic mainly of some Discussion Rhabdochona species. According to Moravec, The classification of the genus (1975) these are the characters of subgenera Rhabdochona Railliet 1916, and its subgenera Globochona and Globochonoides. In our study, based on morphology of eggs, have been discussed light microscope (LM) was used and it is difficult to by several workers (Choquett, 1951; Gustapfson, study small size of these caudal