THREE NEW SPECIES OF ACTINOLAIM NEMATODES FROM INDIA

BY

ZAKAULLAH KHAN, WASIM AHMAD and M. SHAMIM JAIRAJPURI Institute of Agriculture, Shafi House, Qila Road, Aligarh Muslim University, Aligarh-202 002

India

Three new species of Actinolaimidae are described, two belonging to Paractinolaimus Meyl, 1957, and one to Westindicus Thorne, 1967. Paractinolaimus aruprus sp.n., is closely related to P. baldus Thorne, 1967 and P. microdentatus (Thorne, 1939) Meyl, 1957 but differs from the former in having a smaller odontostyle, anterior vulva and longer female tail while from the latter it differs in having longer female tail, shorter spicules and fewer ventromedian supplements. Paractinolaimus vul- vapapillatus sp.n. is distinctive in being short, the posterior location of vulva and presence of papillae on both sides of vulva, and is closely related to P. indicus Khan & Ganguly, 1988 and P. vigor Thorne, 1967. Westindicus keralaensis sp.n. differs from all the three known species viz. W. brachycephalus Thorne, 1967, W. rapax Hunt, 1977 and W. cinctus (Cobb in Thorne, 1939) Thorne, 1967 in the presence of a comparatively short body, short female tail and many ventromedian supplements.

Keywords: Actinolaimidae, Paractinolaimus aruprus sp.n., Paractinolaimus vulvapapillatus sp.n., Westin- dicus keralaensis sp.n.

Soil samples collected from Arunachal Pradesh and Kerala States of India

yielded several nematode species of the superfamily Actinolaimoidea. These

represent three new species. viz., Paractinolaimus aruprus sp.n., P. vulvapapillatus sp.n., and Westindicus keralaensis sp.n.

The nematodes were killed and fixed in 4% formaldehyde, dehydrated by the slow method and mounted in glycerine. Measurements were taken with an ocular micrometer.

DESCRIPTIONS

Paractinolaimus aruprus sp.n.

(Fig. 1)

Dimensions

Paratype females (n = 2): L = 2.27-2.40 mm; a = 30-32; b = 4.4-4.8; c = 8; c' =

8.1-8.4; V = 45-48; G1 = 13-17; G2 = 15-17; odontostyle 24-26 u.m; odon-

tophore 25-26?im; oesophagus 497-513 jJ.m; prerectum 113-150 pm; rectum

45-52 tail 299-315 ABD 38 flm.

?o/o?/?/<?.- L = 2.25 mm; a = 31; b = 4.5; c = 8; c' = 8.1; V = 45; G1 =

13; G2 = 14; odontostyle 23 p-m; odontophore 26 gm; oesophagus 493 )lm;

prerectum 120 p.m; rectum 45 jim; tail 293 gm; ABD 36 gm.

495

Fig. 1. Paractinolaimus aruprus sp.n. A. Entire female; B. Entire male; C. Anterior region; D. Anterior end showing amphid; E. Oesophago-intestinal junction; F. Female gonad (posterior); G. Female

posterior region; H. Male posterior region.

496

Paratype males (n = 2): L = 2.00-2.15 mm; a = 27-33; b = 3.8-4.5; c = 58-71; c'

= 0.7-0.9; T = 53-54; odontostyle 23-24 ¡.1m; odontophore 26 pm; oesophagus 520-547 ¡.1m; spicules 53-59 ¡.1m; lateral guiding pieces 10-12 11m; ventromedian

supplements 9-11; prerectum 180-186 11m; rectum 53-54 gm; tail 30-35 gm; ABD 38-42 ¡.1m.

Adults: Body straight to slightly ventrally curved when fixed, more so in the

posterior region, especially in males. Cuticle finely striated, 2-3 11m thick at

mid-body and 5-6 11m on tail. Lateral chords begin as narrow strands behind

the base of odontostyle and gradually expand to become 1/4-1/3 of correspond-

ing body-width at mid-body.

Lip region off set by a slight depression, rounded and narrower than adjoin-

ing body. Amphids stirrup-shaped, apertures 11-12 11m or about half of lip

region width. Vestibular ring corrugated. Cheilostome armed with four large onchia and numerous denticles arranged in several rows. Odontostyle 1.1-1.2

lip region width long. Guiding ring 'double', fixed ring at 18 11m or 0.8-0.9 lip

region width from anterior end. Odontophore rod-like, 1.3-1.4 times odon-

tostyle length. Post-extension constriction of oesophagus present at 47-50 11m from base of odontostyle and 75-83 jim from anterior end of body. Basal shield

of oesophagus present. Cardia elongate-conoid, 23-24 Jlm or about one-third of

corresponding body-width long. Oesophageal gland nuclei and their orifices

located as follows: DO = 51-56; DN = 54-59; DO-DN = 2.4-3.0; S1N1 = 75-78;

SIN2 = 77-82; S2N = 84-89; S20 = 86-91.

Female: Reproductive system amphidelphic; vulva a small longitudinal slit;

vagina distally sclerotized, 21-23 ¡.1m or about one-third of corresponding

body-width deep. Both sexual branches equally developed; ovaries well devel-

oped, 95-154 Jlm long with oocytes arranged in a single row except near tip. Oviduct 105-157 Jlm long; sphincter present at oviduct-uterus junction. Uterus

120-225 pm long. Prerectum 3-4 anal body-widths long. Rectum 1.2-1.4 anal

body-widths long. Tail 8.1-8.4 anal body-widths long, gradually tapering to

become long filiform with finely pointed tip. A pair of caudal pores present on

each side of tail.

Male: Testes paired, opposed, dorylaimoid; sperms spindle-shaped, 6-8 ¡.1m

long. Spicules dorylaimoid, about 1.4 anal body-widths long. Lateral guiding

pieces 1/6-1/5 of spicules length. Supplements an adanal pair and 9-11 regu-

larly spaced ventromedians. The posteriormost supplement at 78-81 1 pm from

cloacal aperture, others 10-12 gm apart. Prerectum 4-5 anal body-widths long,

terminating just above the last supplement. Rectum 1.3-1.4 anal body-widths

long. Tail bluntly rounded, 0.8 anal body-widths long, with 2-3 caudal pores on

each side.

Type habitat and locality : Soil around roots of banana (Musa paradisiaca L.) from

Itanagar, Arunachal Pradesh, India.

Type specimens: Collected in March 1990, Holotype female on slide Parac-

tinolaimus aruprus sp.n./I; paratype females and males on slides Paractinolaimus

aruprus sp.n./2-4 deposited in the nematode collection of Zoology Department,

497

Aligarh Muslim University, Aligarh. A paratype female and a male deposited at

Instituut voor Dierkunde, Gent, Belgium.

Differential diagnosis: Paractinolaimus aruprus sp.n. is closely related to P. baldus

Thorne, 1967 but differs in having smaller odontostyle, slightly anteriorly located vulva and longer tail (odontostyle 27 p,m, V = 52 and c = 11 in P.

baldus). It is also related to P. microdentatus (Thorne, 1939) Meyl, 1957 but differs

in having narrower lip region, comparatively shorter body, longer female tail, smaller spicules, lateral guiding pieces and fewer ventromedian supplements

(lip region expanded, L = 2.4-3.5 mm, c = 10-14, spicules 67-70 lateral

guiding pieces 18-20 {1m long, ventromedian supplements 20-24 in P.

microdentatus).

Paractinolaimus vulvapapillatus sp.n.

(Fig. 2)

Dimensions "':'oM>

Holotype, female: L = 1.58 mm; a = 34; b = 3.9; c = 9; c' = 6.9; V = 64; G = 13; G2 = 13; odontostyle 22 {1m; odontophore 26p.m; oesophagus 410

prerectum 38 gm; tail 175 ABD 26 gm.

Paratype males (n = 3): L = 1.40-1.50 (1.45) mm; a = 28-32 (30); b = 3.5-3.8

(3.6); c = 57-63 (60); c' = 0.8; T = 56-57; odontostyle 19-20 (20) gm; odon-

tophore 21-23 (22) gm; oesophagus 388-422 (400) gm; spicules 42-45 (44) )lm; lateral guiding pieces 10-12 (11) Rm; ventromedian supplements 9; prerectum 135-138 (137) )lm; rectum 30-38 (34) jim; tail 24 gm; ABD 30 p.m.

Adults: Body strongly ventrally curved when fixed, more prominently in the

posterior region. Cuticle smooth, 2-3 Jlm thick at mid-body and 4-5 Jlm on tail.

Lateral chords about one-fourth of corresponding body-width at mid-body.

Lip region rounded, slightly expanded, set off by a constriction. Amphids

stirrup-shaped, apertures 10 {1m or about half of lip region width wide. Ves-

tibular ring corrugated. Cheilostome armed with four large onchia and

numerous denticles arranged in several rows. Odontostyle about one lip region width long. Guiding ring 'double', fixed ring at 15-18 Jlm or 0. 7-0.9 lip region widths from anterior end. Odontophore simple, rod-like, 1.1-1.2 times odon-

tostyle length. Post-extension constriction of oesophagus present at 42-45 gm from base of odontostyle and 60-71 )Hm from anterior end. Nerve ring at

140-167 pm from anterior end of body. Oesophagus beginning to widen at

48-51% attaining full width at 50-53% of its length from anterior end. Basal

shield of oesophagus present. Cardia elongate-conoid, 17-24 pm long.

Oesophageal gland nuclei and their orifices located as follows: DO = 52-57; DN = 55-58; DO-DN = 2.5-3.1; S1N1 = 74-78; SIN2 = 78-80; S2N = 85-87;

S20 = 86-88.

Female: Reproductive system amphidelphic. Vulva a longitudinal slit, three

vulval papillae present on each side of vulva; vagina 23 Jlm or about one-third

of corresponding body-width deep. Both sexual branches equally developed,

498

Fig. 2. Paractinolaimus vulvapapillatus sp.n. A. Entire male; B. Entire female; C. Anterior region; D. Anterior end showing amphid; E. Oesophago-intestinal junction; F. Female gonad (posterior); G.

Female posterior region; H. Male posterior region.

499

ovaries well developed, 68-75 pm long with oocytes arranged in a single row

except near tip. Oviduct 83-90 pm long; sphincter present at oviduct-uterus

junction. Uterus 108-112 {1m long. Prerectum 2.6 anal body-widths long. Rectum 1.5 anal body-widths long. Tail 6.8 anal body-widths long, gradually

tapering to become long filiform with acute terminus, caudal pores three on each side.

Male: Testes paired, opposed, dorylaimoid; sperms spindle-shaped, 6-8 gm

long. Spicules dorylaimoid, 1.4-1.5 anal body widths long. Lateral guiding

pieces rod-like, about 1/4 of spicules length. Supplements an adanal pair and nine regularly spaced ventromedians, posteriormost at 42-45 Jlm from cloacal

apertures, others 9-11 1 pm apart. Prerectum about 4.6 anal body-widths long; extending much beyond range of supplements. Rectum 1.0-1.4 anal body- widths long. Tail bluntly rounded, 0.8 anal body-widths long, with three caudal

pores on each side.

Type habitat and locality : Soil around roots of forest trees (unidentified) from the Silent Valley, Kerala State, India.

Type specimens: Collected in November 1989. Holotype female on slide Parac-

tinolaimus vulvapapillatus sp.n./ l; paratype males on slides Paractinolaimus vulva-

papillatus sp.n./2 & 3, deposited in the nematode collection of Zoology Depart- ment, Aligarh Muslim University, Aligarh. A paratype male deposited at Instituut voor Dierkunde, Gent, Belgium.

Differential diagnosis: Paractinolaimus vulvapapillatus sp.n. is distinctive in its short

size, posterior location of vulva, and presence of papillae on both sides of vulva. The new species is closely related to P. indicus Khan & Ganguly, 1988, but differs in having shorter body, comparatively short odontostyle and odon-

tophore, shape and position of vulva, presence of vulval papillae and shape and

size of tail (L = 1.5-1.9 mm; odontostyle 22-28 p.m; odontophore 25-35 pm; c =

15-37; V = 53-56; vulva a transverse slit and vulval papillae absent in P. indicus). It further differs from P. indicus in the presence of males (male absent in P.

indicus). The new species is also related to P. vigour Thorne, 1967 but differs from it in

having shorter body, shorter odontostyle and odontophore, posteriorly located

vulva, in the presence of vulval papillae and longer tail (L = 1.98-2.41 mm;

odontostyle 25-28 pm; odontophore 28-34 gm; V = 50-55; vulval papillae absent and c = 10.5-14.0 in P. vigor).

Westindicus keralaensis sp.n.

(Fig. 3)

Dimensions:

Holotypefemale: L = 2.10 mm; a = 37; b = 4.6; c = 20; c' =3.1; V = 54; =

14; G2 = 14; odontostyle 26 pm; odontophore 33 gm; oesophagus 450

prerectum 93 u,m; rectum 38 )lm; tail 100 fim; ABD 33 gm.

500

Fig. 3. Westindicus keralaensis sp.n. A. Entire female; B. Entire male; C. Anterior region; D. Oesophago-intestinal junction; E. Vulval region; F. Female posterior region; G. Male posterior.

501

Paratypemale: L = 2.04 mm; a = 37; b = 4.9; c = 85; c' = 0.68; T = 59;

odontostyle 24 gm; odontophore 33 Fm; oesophagus 413 gm; spicules 54 gm; lateral guiding pieces 15 gm; ventromedian supplements 11; prerectum 138

tim; rectum 50 tail 24 gm; ABD 35 gm. Adults: Body slightly ventrally curved when fixed, more so in posterior region,

especially in males. Cuticle finely striated, 4-5 gm thick at mid-body and 5-6

Jlm on tail. Lateral chords about one-fourth of corresponding body-width wide

at mid-body. Lip region 24-26 gm wide and 8 gm high, set off by slight constriction, expanded with rounded sides. Amphids stirrup-shaped, apertures 9-11 ?im or about two-fifths of lip region-width wide. Cheilostome with four

large onchia. Vestibule with sclerotized ribs forming a basket-like structure.

Walls of stoma bearing minute denticles. Odontostyle length equal to lip

region-width, aperture about two-fifths of its length. Guiding ring 'double', fixed ring at 18-21 1 Fm or 0.7-0.8 lip region widths from anterior end. Odon-

tophore simple, rod-like, 1.3-1.4 times odontostyle length. Post-extension con-

striction of oesophagus at 50 pm from base of odontostyle and 83-87 pm from

anterior end. Nerve ring at 120-132 gm from anterior end of body. Oesophagus

beginning to widen at 46-47% and attaining full width at 50-51 % of its length from anterior end. Oesophageal gland nuclei and orifices obscure. Basal shield

present. Cardia conoid, 20-21 1 Fm long. Female: Reproductive system amphidelphic. Vulva transverse, vagina well

sclerotized, 15 Jlm or about one-third of corresponding body-width deep. Both

sexual branches equally developed, ovaries well developed, 120-140 gm long with oocytes arranged in a single row except near tip. Oviduct 160-185 gm

long, sphincter present at oviduct-uterus junction. Uterus 100-115 gm long. Prerectum 2.9 anal body-widths long. Rectum 1.2 anal body-widths long. Tail

3.1 anal body-widths long and gradually tapering to become elongate conoid.

Male: Testes paired, opposed, dorylaimoid; sperms spindle-shaped, 5-6 gm

long. Spicules dorylaimoid, 1.5 anal body-widths long; lateral guiding pieces

simple rod-like, about one-fourth of spicule length. Supplements, an adanal

pair and 11 ventromedians arranged in series, posteriormost supplement situ-

ated at 68 Jlm from cloacal opening, others 8-11 1 Fm apart. Ventrosubmedian

papillae 6-7 on each side in region of supplements. Prerectum 3.9 anal body- widths long. Rectum 1.4 anal body-widths long. Tail short, dorsally convex

conoid with bluntly rounded terminus, 0.7 anal body-width long. Caudal pores three on each side.

Type habitat and locality : Soil around roots of forest tree (unidentified) from

Trichur, Kerala State, India.

Type specimens: Collected in November 1989. Holotype female on slide Westin-

dicus keralaensis sp.n./ l; paratype male on slide Westindicus keralaensis sp.n./2.

Holotype female deposited in the nematode collection of Zoology Department,

Aligarh Muslim University, Aligarh. Paratype male deposited at Instituut voor

Dierkunde, Gent, Belgium.

502

Differential diagnosis: Westindicus keralaensis sp.n. is characterised by the pres- ence of a comparatively short body, short female tail and many ventromedian

supplements. It differs from W. brachycephalus Thorne, 1967 in having compara-

tively weak onchia, shorter expanded part of oesophagus, shorter prerectum and female tail, more ventromedian supplements and ventrosubmedian

papillae (expanded part of oesophagus about 2/3 of neck length, prerectum two

anal body-widths long; c = 9; ventromedian supplements 5-7 and ventro-

submedian papillae 4 in W. brachycephalus). From W. rapax Hunt, 1977, it differs

in having shorter body, shorter odontostyle, shape of vulva, shorter tail and

number of ventromedian supplements (L = 2.44-2.90 mm; odontostyle 27-31 1

Jim, vulva minute pore-like, c = 8.9-1 1.7 and 8 weakly developed ventromedian

supplements in W rapax). From W. cinctus (Cobb in Thorne, 1939) Thorne, 1967 it differs in having more slender body, wider lip region and longer

odontostyle (lip region 15 odontostyle 17 [tm; a = 32 in W. cinctus).

This research work was supported by grants from the ICAR and the CSIR, New Delhi.

RÉSUMÉ

Trois nouvelles espèces d'Actinolaimides provenant de l'Inde

Trois nouvelles espèces d'Actinolaimidae sont décrites, deux appartenant au genre Parac- tinolaimus Meyl, 1957, la dernière à Westindicus Thorne, 1967. Paractinolaimus aruprus sp.n. est très proche de P. baldus Thorne, 1967 et de P. microdentatus (Thorne, 1939) Meyl, 1957; il diffère de la première espèce par l'odontostyle plus court, la vulve plus antérieure et la queue plus longue de la femelle, et de la seconde espèce par la queue plus longue de la femelle, les spicules plus courts et un plus faible nombre de suppléments ventro-médians. Paractinolaimus vulvapapillatus sp.n. est carac- térisé par sa petite taille, la localisation postérieure de la vulve et la présence de papilles des deux côtés de la vulve; il est proche de P. indicus Khan & Ganguly, 1988 et de P. vigor Thorne, 1967; W. keralaensis sp.n. diffère des trois autres espèces du genre, W. brachycephalus Thorne, 1967, W. rapax Hunt, 1977 et W. cinctus (Cobb in Thorne, 1939) Thorne, 1967, par sa taille plus faible, la queue courte de la femelle et le grand nombre de suppléments ventromédians.

REFERENCES

HUNT, D. J. (1978). Stomachoglossa bryophilus sp.n. (Brittonematidae), Westindicus rapax sp.n. (Parac- tinolaimidae), Caribenema siddiqii sp.n. and C. longidens Thorne, 1967 (Carcharolaimidae) from St. Lucia. Nematologica 24, 175-183.

KHAN, E. & GANGULY, S. (1988). Paractinolaimus indicus sp.n. (Nematoda: Dorylaimida) and its morphological variability. Indian Journal of Nematology 18, 291-294.

MEYL, A. H. (1957). Free-living nematodes. In: Exploration Hydrobiologique du lac Tanganika (1946-47). Institut Royal des Sciences Naturelles de Belgique 3, 27-51.

THORNE, G. (1939). A monograph of the nematodes of the superfamily Dorylaimoidea. Capita Zoologica 8, 1-261.

THORNE, G. (1967). Nematodes of Puerto Rico: Actinolaimoidea new superfamily with a revision of its genera and species with addenda to Belondiroidea (Nematoda: Adenophorea, Dory- laimida). University of Puerto Rico Agriculture Experiment Station Technical paper 43, 48 pp.