Japan. J. Med. Sci. Biol., 18, 143-150, 1965

ON A NEW OF A (THELAZIIDAE, SPINITECTINAE, SPINITECTUS, FOURMENT, 1883) WITH A KEY TO THE SPECIES OF THE SPINITECTUS

UMAPATI SAHAY AND DEVENDRA PRASAD Department of Zoology, Science College, Patna-5, Bihar., India

INTRODUCTION

The systematic position of the genus Spinitectus has been a matter of great dispute. This genus was included in the family Rictulariidae under subfamily Rictulariidae by Yorke and Maplestone in the year 1962. The genus, however, was placed as an ap- pendix to the subfamily Thelaziidae by Baylis and Daubney in 1926. In 1928 it had to occupy another position of being included in the new subfamily Rhabdochoninae by Travassos, Artigas and Pereira. They included three genera in the new subfamily Rhabdochoninae, viz., Railliet, 1916; Spinitectus Fourment, 1883 and Cystidicola Fischer, 1798. The authors did recognize the fundamental similarity of structure among these genera besides their common property of being parasitic in the same group of hosts the fishes. In 1946 Skrjabin included all Spirurata of fishes into a new family Rhabdochonidae which consisted of three subfamilies viz., Rhabdochoninae, Cystidicolinae and Spinitectinae. This attitude of including three subfamilies into the family Rhabdochonidae was adopted by Skrjabin in order to support and emphasize the host relationship between them. The authors, however, are not in favour of raising the same to the family rank but agree with Travassos in creating the subfamily Rhabdo- choninae to accommodate the related forms. The authors also agree with the views of Ali (1956) to raise the genera Rhabdochona, Cystidicola and Spinitectus to the subfamily status with their inclusion in the family Thelaziidae. In fact, the type genera of the three subfamilies were originally included in the family Thelaziidae by Baylis and Daubney (1926). They however were unjustified in reducing the family Thelaziidae to the subfamily rank. Yorke and Maplestone (1926) were justified in shifting the Spini- tectus from Rictulariidae to the family Thelaziidae on the ground that the stoma of Spinitectus differed radically from that of Rictularia.

Spinitectus koniivai n. sp. Spinitectus indicus was first recorded from Eutropichthys vacha and Pseudotropius garua by Verma, S. C. and Agarwala, M. P. in 1932. The authors have collected a number of specimens of a nematode of the genus Spinitectus from the same host i, e., Eutropichthys vacha at Patna in the state of Bihar (INDIA) in the year 1964 while making helminth collections from fishes of Bihar. The present specimen, however, differs remarkably from that described by Verma and Agrawala in 1932. Owing to the presence of characteristic spines on its body, the nematode is clearly referable to the genus Spinitectus Fourment, 1883; and owing to its characters very peculiar to it compairing all the species described till now, the authors feel the pleasure

143 144 SAHAY et PRASAD Vol. 18 in giving it a status of a new species and naming this worm after Dr. Y. Komiya, Chief of Department of Parasitology, National Institute of Health, Tokyo, Japan. The present communication is based upon the study of two male and eleven female specimens collected from the intestine of Eutropichthys vacha. Out of a lot of 5 speci- mens of the fish only two were found to be infected.

DESCRIPTION

The bodies of the worms are long and slender. The females were found to be larger than the males. The body in both the sexes tapers slightly at the head. The tail in the female ends into a pointed spine. This spine is borne on a knob like structure laterally serrated whereas the tail in the case of males is laterally curved ending into a spine. In the living condition they are often attached to the wall of the intestine. The cuticle bears spiny annulations which are characteristic of the genus Spinitectus. In the species described herein rings of spines present on the body vary in number from 18 to 20. The spines are very distinct in front, becoming progressively less prominent posteriorly, whilst they are not descernible behind the level of the junction of the oeso- phagus and the intestine. The first two rings which are best developed are 0.032 mm apart in the male and 0.031 mm in the female. The largest spine in the first ring measures 0.018 mm both in the male and female, while in the 2nd ring the largest spine measures 0.022 mm in male and 0.018 mm in female worms. Distinct lips on the head have not been seen. There are three pairs of cephalic papillae of which two pairs are sub-median and one lateral in position. The terminal mouth leads into a funnel shaped vestibule measuring 0.0315 mm long in the male and 0.036 mm in the female. The oesophagus is very long and is clearly marked into a muscular and glandular portion. The constituent muscular and glandular portions of the oesophagus measure 0.31 mm to 0.32 mm and 1.29 mm to 1.29 mm, respectively, in the male and 0.35 to 0.352 mm and 1.38 mm to 1.40 mm in the female. The opening of the oesophagus into the intestine is guarded by the oesophageo-intestinal valves which are quite prominent. The nerve ring encircles the muscular portion of the oesophagus towards its anterior end and is 0.13 mm from the head end in the male and 0.19 mm in the female. Excretory pore could not be located even after a prolonged search. Male: The body is small and very slender, measuring 8.1 to 8.476 mm in length and 0.20 mm in greatest width. There is a single filiform testis reaching up to the anterior third of the body. The tail of the male is curved ventrally and the cloacal aperture is 0.183 to 0.187 mm from the tip of the tail. The caudal alae are well developed extending along the sides of the body. There are eight pairs of papillae out of which four pairs are pre-anal and the rest are post-anal. The spicules are markedly unequal in size and different, in shape. The left spicule which is longer of the two measures 0.25 mm in length and the right measures 0.09 mm, their lengths being in the ratio of 2.7; 1.0. Female : The female varies in length from 10.20 to 10.46 mm and has an average transverse diameter of 0.32 mm. The conical tail measures 0.23 mm in length. The vulva is flush with the body surface and is situated at a distance of 4.50 mm from the anterior end. The vulva opens into a muscular vagina. The uteri communicate by means of narrow oviducts with the filiform ovaries, which run in the opposite direction. The uteri contained eggs which were found to be thick shelled and non-embryonated. 1965 A NEW SPECIES OF A NEMATODE 145

Fig. 1. Posterior end male (Lateral view) •~ 200.

P., Papillae ; LT. S., Left Spicule ; RT. S., Right Spicule.

Fig. 2. Anterior end male. G. OES., Glandular oesophagus ; M. OES., Musdular Oesophagus ; NR., Nerve ring ; S. VES., Vistibule. 146 SAHA Y et PRASAD Vol. 18

Fig. 3. Posterior end female. AN., Anus ; TNT., Intestine ; RECT., Rectum.

The eggs measured 0.036 •~ 0.022 mm.

Host : Eutropichthys vacha.

Habitat : Intestine.

Locality : Patna, Bihar (India).

DISCUSSION

The genus Spinitectus was established by Fourment (1883) with S. oviflagellis as its type. Zeder (1800) described Goezia inermis which was later on transferred to the genus Spinitectus as Spinitectus inermis. This species was redescribed in the year 1927 by Neveu Lemaire. Spinitectus echinatus described in 1878 by Linstow has been referred to as a larval from of S. inermis by Yorke and Maplestone and as synonym of S. oviflagellis by Moristha. Till recently 27 species** of Spinitectus are known.

** (1) S. inermis Zeder, 1800; Rud, 1800 (2) S. echinatus Linstow, 1878 (3) S. oviflagellis Fourment, 1883 (4) ,S minor Stewart, 1914; Baylis 1939 (5) S. cristatus Railliet and Henery, 1915 (6) S. gracilis Ward & magath, 1917 redescribed by Mueller & Von Cleave 1932 (7) S. ranae Morishita, 1926 (8) S. gigi Fuijita, 1927 (redescribed by Yamaguti in 1935) (9) S. yorki Travassos, Artigas & Pereira, 1928 (10) S. carolini Holl, 1928 (rede- 1965 A NEW SPECIES OF A NEMATODE 147

Fig. 4. Anterior end female. G. OES., Glandular oesophagus ; M. OES., Musdular Oesophagus ; NR., Nerve ring ; VES., Vestibule.

The present worm under discussion differs from all*** the species known but resembles S. longipapillatus (Ali, 1956) in the possession of a similar number of caudal papillae i. e., 4 pre-anals and 4 post-anals, but differs from it in the following points ; (1) Lengths of spicules are in the ratio of 2.04: 1 in S. longipapillatus & 2.74: 1 in S. komiyai. n. sp. (2) Sessile caudal papillae at the tip of the tail of S. longipapillatus are altogether absent in S. komiyai n. sp.

scribed by Mueller & Von Cleave, 1932) (11) S. guntheri Baylis, 1929 (12) S. indicus Verma and Agrawala, 1932 (13) S. rodolophiheringi Vaz and Pereira, 1934, (14) S. mogu- rundae Yamaguti, 1935 (15) S. corti Moorthy, 1938 redescribed by Au, 1956) (16) S. plectroplites Johnston & Mawson, 1940 (17) S. percaletes* Johnston and Mawson, 1940 (18) S. bancroftei Johnston and Mawson, 1940 (19) S. notopteri Karve and Naik, 1951 (20) S. mastacembeli Karve and Naik, 1951 (21) S. neilli Karve and Naik, 1951 (22) S. major Khera, 1956 (23) S. armatus Au, 1956 (24) S. longipapillatus Au, 1956 (25) S. singhi Ali. 1956 and (26) S. thapari. 1956. *** Our specimens could not be compared with S. guntheri, Baylis 1929; 5. inermis Zeder, 1800; S. echinatus Linstow, 1878; S. oviflagellis Fourment, 1883 due to the non-availability of the accounts.

•™ According to Khera S. percalates is synonym with S. plectroplites. 148 SAHAY et PRASAD Vol. 18

(3) Both males and females of S. longipapillatus are very small (male 3.93 mm, female 3.98 mm) as compared to S, komiyai n, sp. (male 8.40 mm ; female 10.45 mm). (4) The ratio of the lengths of muscular and glandular oesophagus in S. longi- papillatus is approximately 3 : 1 whereas in S. komiyai n, sp. it is approximately 4 : 1. (5) Vulva is situated at about the junction of middle and posterior thirds of the body in S. longipapillatus whereas it is slightly anterior to the middle of the body in S. komiyai n. sp..

The characters given by Verma and Agrawala, 1932 for Spinitectus indicus are

Spicules equal, 5 preanal and 4 post anal caudal papillae, head not distinctlly marked off from the body, oesophagus is very long not marked off into an anterior and posterior portion, alae being absent. Our specimens i. e., Spinitectus komiyai n. sp. show the following characters : •\ (1) Spicules distinctly unequal & dissimilar (ratio being 2.74: 1). (2) Oesophagus consista of two distinct parts (ratio between the anterior muscular and glandular posterior portion being 4 : 1 both in male and female specimens .) (3) Caudal alae present. (4) Vulva situated at a distance of 4.50 mm from the anterior end. (5) The tail in the female ends into a spine which is borne on a knob-like structure laterally serrated.

On comparison, our specimens do not resemble S . indicus in any case though both the worms were recovered from Eutropichthys vacha. Besides the characters , oesophagus consisting of two parts muscular and glandular, the presence of narrow alae are definite generic characters (This has been mentioned in "The nematode parasites of •h by Yorke and Maplestone 1926 Edition ; "TheThe fauna of British India including Ceylon & Burma•h by H. A. Baylis Nematoda Vol. II, 1939; and •hSystema Helminthum•h Nematoda Vol. III by S. Yamaguti 1961). The presence of spines into definite rings throughout the body of S. indicus is a strong proof for its inclusion into the genus aSpinitectus. In view of the above discussion the observations of the worms S . indicus having no alae or oesophagus not marked into an anterior and posterior portion has to be reconsidered. The type specimens of this species described in this part are deposited in the Helmin- thology section of the department of Zoology, Science College , Patna-5, Bihar.

KEY TO THE SPECIES OF THE GENUS SPINITECTUS Fourment, 1883

1. Parasites of Amphibia ...... S. ranae, Moristha, 1926. Parasites of fishes ...... 2 2. Eggs with polar filaments ...... S. oviflagellis, Fourment, 1883. Eggs without polar filaments ...... 3 3. Spicules equal ...... S. indicus Verma & Agrawala , 1932. Spicules unequal...... 4 4. Caudal papillae (20 pairs) ...... S. yorkei Travassos, Artigas & Pereira, 1928. Caudal papillae less than 20 pairs ...... 5 1965 A NEW SPECIES OF A NEMATODE 149

5. Left spicule more than three times the length of the right spicule...... 6 Left spicule three times as long as right spicule ie., spicule ratio is 3:1 (L. S 0.17 mm R. S 0.05 mm)...S. bancroftei Jhonston & Maw- son, 1940 Left spicule less than three times the length of the right spicule...... 7 6. Spicule ratio 8 . 1 (L. S 0.64, R. S 0.081 mm) ...... S. singhi Ali, 1956. Spicule ratio 7 : 1 ...... 8 Spicule ratio 6 : 1 ...... 9 Spicule ratio 5 : 1 + male and female less than 2mm (L. S 0.25-0.26 mm, R. S 0.052-0.055 mm) ...... S. corti Moorthy, 1938. Spicule ratio 4 : 1 ...... 10 7. Spicule ratio 2.74: 1 (L. S 0.247, R. S 0.09 mm) ... S, komyai n. sp. Spicule ratio 2 : 1 ...... 11 Spicule ratio 1/2: 1 (L. S 0.15, R. S 0.09 mm) ...... S. percilatus Jhonston & Maw- son- 1940. Spicule ratio 1.66: 1 (L. S 0.2, R. S 0.12 mm) ...... S. rodolphiheringi Vaz and Pereira, 1934. 8. Caudal papillae 10 pairs ...... S. thapari Ali, 1956. Caudal papillae 7 pairs ...... S. minor, Baylis, 1939. 9. Caudal papillae more than 10 pairs ...... 12 Caudal papillae 10 pairs ...... 13 Caudal papillae less than 10 pairs...... 14 10. 9 pairs of caudal papillae, vulva equatorial (L. S 0.27, R. S 0.07 mm) ...... S. carolini Muller, Von Cleave, 1932 11. Caudal papillae 9 pairs ...... S. nellie, Karve & Naik, 1951, Caudal papillae 8 pairs ...... S. long ipapillatus Ali, 1956. 12. Caudal papillae 16 pairs ...... S. notopteri Karve and Naik, 1951. Caudal papillae 12 pairs ...... S. mastacembeli Karve and Naik, 1951. 13. First three rows of spines closer ...... S. armatus Ali, 1956. First two rows of spines closer ...... 15 14. Caudal papillae 9 pairs ...... S. major Khera, 1956. 15. Vulva devides the body in the ratio of 21: 1...... S. gigi Fuijita, 1927

The authors wish to express their thanks to Dr. P. D. Gupta, Superintendent Zoologist, Zoological Society of India ; Professor Syed Mehdi Ali, Head of the department of Zoology, Marathwada University, Aurangabad ; Dr. Satayendra Khera, Reader Jodhpur University, India for their constant encouragement and interest throughout the work. Thanks are also due to Mrs. Sarojani Narayan, Sarbesh nath and Shiva Ishwar Dayal for the collection of literature. One of us (U. S) records his thanks to Dr. S. A. Majid Principal, College of Commerce, Patna-6 for kindly recommending him for a research grant and Dr. K. K. Dutta, the Vice Chancellor, Magadh University, Gaya, India for the financial assistance. The authors are also indebted to Dr. Y. Komiya, the National Institute of health, Tokyo, Japan, for critically going through the manuscript. 150 SAHAY et PRASAD Vol. 18

REFERENCES

ALI S. M. (1956): Studies on the nematode parasites of fishes and found in Hydrabad State. Indian. J. Helminthol., 8, 1-83. BAYLIS, H. A. (1929): The life histories of some . J. Quek. Micr. Club, 16, 107-124. BAYLIS, H. A. (1929): Parasitic nematoda and Acanthocephala Discovery Rep. 1, 544-559. BAYLIS, H. A. (1929): Some new parasitic nematodes & Cestodes from Java Parasitol, 21, 256-265. FUIJITA, T. (1927): On new species of nematodes from fishes of lake Biwa. Japan. J. Zool, 1, 169-176. FUIJITA, T. (1927): Parasitic nemathelminthes found in fishes of lake Biwa. " Dobuts Zasshi ", 39, 39-45; 157-161; Japan. J. Zool. 2 86-87, 88. JOHNSTON, T. H. & MAWSON, P. M. (1940): Some nematodes parasitic in Australian fresh water fishes. Tr. Roy. Soc. Austr. 64, 340-352. JOHNSTON, T. H. & MAWSON, P. M. (1940): Some nematode parasitic in Austrailian fresh water fishes, Tr. Roy. Soc. Austr. 64, 95-100. KARVE, J. N. & NAIK, G. G. (1951): Some parasitic nematodes of fishes II. J. Univ. Bombay, Biol. Sci, n. s. , 19, 1-37. KHERA, S. (1956): Nematode parasites of some Indian Vertebrates, Indian. J. Helminthol., 6, 27-133. LINSTOW, O. VON (1874): Neue Beobachtungen an Helminthen. Arch. Naturg. 44. J. 1, 218-245. MOORTHY, V. N. (1938): Spinitectus corti n. sp. (Nematoda: Spiruridae). J. Parasitol., 24, 323-322. STEWART, F. H. (1914): Studies in Indian Helminthology, No. I. Rec. Ind. Mus., 10 (3), 165-193. VERMA, S. C. & AGRAWAL, M. P. (1932): A new species of Spinitectus a nematode from India. Rec. Ind. Museum. 34, 263-268. WARD, H. B. & MAGATH, T. B. (1917): Notes on some nematodes from fresh water fishes. J. Parasitol., 3, 57-64. YAMAGUTI, S. (1935): Studies on the helminth fauna of Japan Nematodes of fishes. Japan. J. Zool. 6, 337-386. YAMAGUTI, S. (1961): Systema Helminthum Vol. III, Part I & II, Inter-Science Publishers, INC., New York, London. YORKE, W. & MAPLESTONE, P. A. (1926): The nematode parasites of vertebrates J. & A. Churchill, 7 Great Marlborough Street.