ON FOUR NEW NEMATODE SPECIES OF THE GENUS DIPLOTRIAENA RAILLIET AND HENRY , 1909 , FROM UTTARAKHAND , INDIA

In the course of a faunistic survey in Almora, Champawat and Pithoragarh districts of Uttarakhand (then Uttar Pradesh) was undertaken during March-April t 1990, several helminth parasites were collected by thr first author from a number of birds and mammals of that region. The present paper deals with the descriptions of four new species of avian nematodes belonging to the genus Diplotriaena Railliet and Henry, 1909. All measurements are in millimeter.


INTRODUCTION
In the course of a faunistic survey in Almora, Champawat and Pithoragarh districts of Uttarakhand (then Uttar Pradesh) was undertaken during March-April t 1990, several helminth parasites were collected by thr first author from a number of birds and mammals of that region.The present paper deals with the descriptions of four new species of avian nematodes belonging to the genus Diplotriaena Railliet and Henry, 1909.All measurements are in millimeter.

SYSTEMATIC ACCOUNT
Order SPIRURIDA Superfamily DIPLOTRIAENOIDEA Family DIPLOTRIAENIDAE (Skrjabin, 1916, subfam.)Anderson, 1958 Subfamily DIPLOTRIAENINAE SKRJABIN, 1916 Genus DIPLOTRIAENA Railliet and Henry, 1909 Diagnosis: Body finely striated and rounded at both extremities; no lips; one pair of cephalic papillae on each side of the head; trident-like structures present on either side of anterior end of oesophagus and opening by pores on either side of the oral opening; the prongs of the tridents being equal, striated and with rounded tips; oesophagus divided into two parts; eight pairs of caudal papillae in male; spicules unequal, dissimilar and non-alate; vulva at glandular oesophageal portion of the body.
Description : Male.Body 23.84 mm long, 0.56 mm wide; tridents two in number, prongs equal, striated and with rounded tips, 0.272 mm long; nerve ring at 0.288 mm from the anterior end; oesophagus divided into two parts, an anterior, narrower and muscular, 0.288 mm long, 0.048 mm wide, and a posterior wider, glandular, 1.472 mm long, 0.16 mm wide; entire oesophagus 1.76 mm long; spicules unequal and dissimilar, left longer, tubul~r, ventrally curved, 1.312 mm long, non-alate with pointed tip; right spicule smaller, cork-screw shaped, about 1 Y2 turns, 0.72 mm long in straight line and 0.88 long in curvature, non-alate; cloaca sub-terminal at 0.117 mm from the posterior end; caudal papillae 8 pairs, 2 pairs pre-anal and the rest post-anal in position.
Female: Body 46.56-56.64mm long, 0.75-0.80mm wide; trident as in the male, 0.176-0.240mm long; nerve ring at 0.272-0.30mm from anterior end; vulva at 0.528-0.560mm from anterior end; anus terminal; eggs embryonated, 0.032 x 0.048 mm in diameter.Discussion: The present species differs from all other recorded species of the genus in various body llleasurements and in the number and arrangement of caudal papillae in the male.Hitherto, two species Diplotriaena mukteswarensis Singh, 1962 and Diplotriaena nepalensis Soota and  Chaturvedi, .1967are described from the same specific host i. e., Myiophoneus caeruleus temmincki from India (Mukteswar-Kumaun, Uttarakhand) and Nepal respectively.The present species differs from them in the following respect: in D. mukteswarensis the left spicule is smaller (0.979 mm vs. 1.312 mm), caudal papillae 6 pairs, 2 pairs preanal, 2 pairs adanal large and 2 pairs postanal in position where as the present species having 8 pairs of caudal papillae of equal size, 2 pairs preanal and the rest postanal; in D. nepalensis body is longer (38.2 mm vs. 23.84mm), both the spicules are smaller (left 1.0 mm and right 0.64 mm long vs. left 1.312 mm and right 0.72 mm long), caudal papillae 5 pairs (4 + 1 + 0 vs. 8 pairs (2 + 0 + 6).
It is therefore, regarded as new and a specific name Diplotriaena champawatensis sp.n. is being proposed to accommodate it.oesopgagus divided into two parts, an anterior muscular and narrower, 0.32 mm long, 0.032 mm wide and a posterior wider and glandular, 1.92 mm long; entire oesophagus 2.24 mm long; spicules unequal and dissimilar, the left being longer, more or less straight, 0.656 mm long, the right shorter, spiral about one turn, 0.448 mm long in straight line and 0.528 mm in curvature; cloaca subterminal, 0.112 mm from the posterior end; caudal papillae 7 pairs of equal size, 5 pairs preanal and two pairs post-anal, terminal; of the pre-anals 2 pairs ventral and 3-pairs lateral in position.
Discussion: Though a single specimen was available for study, the present species differs from the closely related species thus: from Diplotriaena mukteswarensis Singh, 1962, in the size of spicules, size and shape of the prongs of the tridents, and in the number and position of the caudal papillae (in D. mukteswarensis, male body 24.042 mm long, prongs of the tridents equal, 0.196 mm long, spicule left 0.979 mm and right 0.745 mm long; caudal papillae 6 pairs (2 + 2 + 2); from Diplotriaena chandragiriensis Soota and Chaturvedi, 1971, in the size of spicules, number and arrangement of caudal papillae (in D. chandragiriensis male body 22.0 mm long, spicules left 0.77 mm and right 0.55 mm long; caudal papillae 5-6 pairs [4 Hence, it is regarded as new to science and a specific name Diplotriaena zootherae sp.n. is being proposed to accommodate it.Description: Male.Body 24.0-24.4mm long, 0.496-0.512mm wide; tridents two in number, 0.128 mm-0.144mm long; prongs equal, unstriated and with rounded tips; nerve ring at 0.224 mm-O.240mm from the anterior end; oesophagus divided into an anterior narrower and muscular and a posterior glandular and wider portion; the anterior muscular portion 0.352 mm long, 0.032 mm wide and the posterior portion 2.288 mm long, 0.064 mm wide; entire oesophagus 2.64 mm long; spicules unequal, dissimilar, non-alate, with pointed tips; the left longer, 0.656-0.720mm Female : Body 36.0-36.4mm long, 0.72-0.80mm wide; tridents as in the male, 0.128-0.144mm long; nerve ring at 0.256 mm from the anterior end; oesophagus as in the male, the junction of oesophagus and intestine not traceable due to heavy deposition of eggs; vul va at 0.40-0.448mm from the anterior end; anus almost terminal; eggs 0.024-0.032mm x 0.032-0.048mm in diameter. Discussion: The species under study approaches nearer to Diplotriaena mukteswarensis Singh, 1962, Diplotriaena chandragiriensis Soota and Chaturvedi, 1971and D. doonensis Soota and Tripathi, 1975 in the relative body size and of the size of the prongs of the tridents, but it differs from them in the number and arrangements of caudal papillae in the male and the relative size of .the spiCUles.It is nearer to D. molpastisi Majumdar and Chakravarty, t 963 in the size of spicules (in D. molpastisi left spicule 0.65mm and the right spiocule 0.45 mm long), but differs from it in various body measurements, size and shape of the prongs of the tridents, number and arrangement of caudal papillae (in D. moipastisi tridents 0.15 mm long and the prongs being corrugated, caudal papillae 10 pairs, 4 pairs pre-anal and 6 pairs post-anal.Further, it is closer to D. tricuspis (Fedchenko, 1874) Seurat, 1915, in the number of caudal papillae in male but differ from it thus: in various body measurements, in the arrangement of caudal papillae, D. tricuspis having a variable number of caudal papillae, 9-14 pairs, of them 3-4 pairs being pre-anal; in having longer spicules, left 1.0-2.5 mm and right 0.55-0.96mm long, but the present species having 12 pairs of caudal papillae, one pair pre-anal and the rest post-anal and left spicule up to 0.72 mm and the right up to 0.496 mm long.Therefore, the present species regarded as new and a new specific name Diplotriaena niltavae sp.n. is proposed to accommodate it.Description: Male.Body 39.2 mm long, 0.32 mm wide; tridents with unstriated equal prongs, and rounded tips, 0.16 mm long; nerve ring at 0.32 mm from the anterior end; oesophagus divided, anterior portion narrower and muscular, 0.32 mm long, and the posterior portion wider and glandular, 1.28 mm long; entire oesophagus 1.60 mm long; spicules unequal and dissimilar, the left longer, ventrally curved, 0.848-1.072mm long and the right being shorter and spiral about one turn, 0.448-0.560mm long; spicules ratio about 1 : 1.9; caudal papillae 5 pairs, 1 pair pre-anal and 4 pairs post-anal, terminal in position; cloaca at 0.08 mm from the posterior end.

Female: Unknown.
Discussion: The present species comes closer to Diplotriaena doonensis Soota and Tripathi, 1975, in number and arrangement of caudal papillae but differs from it in body length, size and shape of the prongs of tridents, size and ratio of spicules (in D. doonensis body being 21.6-24.0lllIn long in males; prongs equal with transverse markings, 0.19-0.20 mm long; spicules, left 0.88 Inm and right 0.6-0.66mrfl long and their ratio being 1 : 1.5).It also approaches nearer to D. kUl1zaullensis Singh, 1962, D. nepalensis Soota and Chaturvedi, 1967and D. chandragiriensis Soota and chaturvedi, 1971, in number of caudal papillae, but differs from them in the arrangement of caudal papillae and their relative body measurements and the length of spicules (in D.

kUl1zaunensis
male body being 22.1 mm long, length of prongs of tridents 0.15mm, left spicule 0.623 mm and right spicule 0.418 mm long, caudal papillae 5 pairs ( = 3 + 1 + 1); in D. nepalensis male body being 38.2 mm long, prongs 0.18 mm long, left spicule I.Omm and the right spicule 0.64 mm long, caudal papillae 5 pairs (= 4 + 0 + 1); in D. chandragiriensis male body 22.0 mm, prongs O. 13 mm, left spicule 0.77mm and the right spicule 0.55mm long, caudal papillae 5-6 pairs [ = 4 + 0 + (l -2)].It also differs markedly from all other species known under the genus and from different hosts in the number of caudal papillae and size and shape of spicules.Therefore, the present species is regarded as different from all known forms under the genus Diplotriaena Rail1iet and Henry, 1909, and is named Diplotriaena alrnoraensis sp.n.SUMMARYThe paper deals with four new species of the genus Diplotriaena Railliet and Henry, 1909, of avian nematodes from Almora and Champawat districts, Uttarakhand, India.