Taxonomy of the genus Doryllium Cobb, 1920 (Nematoda: Dorylaimida) with description of two new and a known species
Author
Ahmad, Wasim
Author
Ahad, Sumaya
Author
Islam, Md. Niraul
Author
Sturhan, Dieter
text
Zootaxa
2018
2018-06-27
4441
2
261
278
journal article
29778
10.11646/zootaxa.4441.2.4
8c18255f-0cb3-45f7-a763-5eba38606f83
1175-5326
1301825
293FEFDD-21D8-4C3A-A4B6-93179C2DE585
Doryllium minor
Jairajpuri, 1963
(
Figs. 1–3
)
Material examined.
Eighty-two females from seven different localities, most of them in good state of preservation.
Description.
For measurements, see Table 1.
Female:
Slender nematodes of small size; body cylindrical, slightly curved ventrad upon fixation, tapering slightly towards the anterior extremity, posteriorly ending in a rounded tail. Cuticle with two distinct layers, 2.0 µm thick at midbody and 3–4 µm on tail. Outer cuticle with fine transverse striation; inner layer with distinct transverse striations. Lateral chords occupying about one-fourth to one-third of the midbody diameter. Lip region slightly offset by a weak constriction, 2.0–2.5 times as wide as high and about one-third of body diameter at neck base; lips amalgamated, with rounded contour, inner portion transformed into a perioral disc. Amphids cup-shaped, aperture occupying about one-half of the lip region diameter. Stoma a truncate cone. Odontostyle 0.8–1.1 times the lip region diameter long, aperture about one-fourth of its length. Odontophore with distinct basal knobs, 1.4–2.0 times the odontostyle length. Guiding ring simple, refractive, at 0.8–1.0 times lip region diameter from anterior end. Pharynx consists of a slender and weakly muscular anterior part, separated from basal bulb by a constriction. Pharyngeal bulb cylindroid, occupying about 22–27%of total neck length. Pharyngeal glands often visible. Cardia short, rounded to conoid, about one-fifth to one-fourth of midbody diameter long. Nerve ring located at 42–49% of neck length from anterior end. Genital system monodelphic-opisthodelphic. Ovary reflexed, measuring 39–127 µm long; oocytes arranged in single row except near tip. Oviduct joining the ovary subterminally, separated from the uterus by a narrowing, but with no apparent sphincter seen. Anterior genital branch absent or a rudimentary sac, less than one-third of corresponding body diameter. Vagina cylindrical;
pars proximalis vaginae
4–8 µm long, wall encircled by muscles;
pars distalis vaginae
short, 1.5–2.0 µm long with slightly curved walls;
pars refringens
absent. Vulva apparently a transverse slit. Prerectum 3.3–4.9 anal body diameters long. Intestine-prerectum junction guarded by three cells. Rectum 0.8–1.0 anal body diameter long. Tail cylindroid, hemispheroid to slightly clavate terminus, 1.3–2.0 anal body diameters long, cuticle at tail terminus thick, hyaline portion of the tail variable; caudal pores two on each side.
Male:
Not found
Habitats and localities.
Soil samples collected from around rhizosphere of forest trees from:
1
Dachigam National Park
,
Srinagar
,
Jammu
&
Kashmir
,
India
;
34o8’36”N
75o2’16”E
2
Baramullah
,
Kashmir valley
,
Jammu
&
Kashmir
,
India
;
34o11’52.8”N
74o21’50.4”E
3
Kangna valley
,
Ganderbal district
, Jamuu & Kashmir state,
India
;
34o9’36”N
75o33’0”E
iv).
Kigwema
,
Kohima district
,
Nagaland
,
India
; 25o60’62”N, 94o12’70” E
4
Gudalur
,
Theni district
,
Tamil Nadu
,
India
;
11o50’30”N
,
76o49’17”E
5
Ooty
,
Nilgiris district
,
Tamil Nadu
,
India
;
11°24'0" N
,
76°42'0"E
6 vii
).
Freiburg
,
Germany
;
47°59'56”N
,
7°50'31"E
FIGURE 1.
Dorylllium minor
Jairajpuri, 1963
. A. Entire female; B. Anterior region; C. Anterior end showing amphid; D. Pharyngeal region; E. & F. Pharyngeal bulb; G. Female genital system; H&I. Female posterior region..
TABLE].
Measurements of
Doryllium minor
Jairajpuri, 1963
. (All measurements in µm)
Characters
|
Dachigam
|
Baramullah
|
Kangan Valley
|
Kigwema,
|
Gudalur,
|
Ooty,
|
German population
|
National Park
|
(Kashmir)
|
(Kashmir)
|
Nagaland
|
Tamil Nadu
|
Tamil Nadu
|
(Kashmir)
|
population
|
population
|
population
|
population
|
population
|
population
|
Females
|
Females
|
Females
|
Females
|
Females
|
Females
|
Females
|
n |
13 |
15 |
14 |
9 |
6 |
15 |
10 |
L |
452.5±32.4 |
459.7±19.1 |
414.4±20.2 |
407.4±22.0 |
419.7±27.9 |
461.4±21.4 |
457.5±32.2 |
(416—539) |
(424—491) |
(380—449) |
(366—435) |
(378.2—449.8) |
(425.3—514.5) |
(417.4—513.5) |
Body diameter at neck base |
16.8±1.2 |
16.8±0.8 |
15.8±0.5 |
16.3±0.9 |
16.8±1.5 |
17.1±0.70 |
15.7±0.77 |
(14—19) |
(15—18) |
(14.5—16.5) |
(14—17) |
(13.7—18.6) |
(15.6—18.6) |
(14.7—16.6) |
Body diameter at midbody |
18.07±1.05 |
17.3±0.6 |
16.5±0.6 |
17.6±1.0 |
17.4±1.4 |
17.9±0.72 |
16.6±0.57 |
(16—20) |
(16—18) |
(15—17.5) |
(16—20) |
(14.7—18.6) |
(17.1—19.6) |
(15.6—17.6) |
Body diameter at anus |
12.1±0.6 |
11.5±0.8 |
11.0±0.5 |
12.6±0.6 |
11.7±1.2 |
12.6±0.86 |
11.8±0.70 |
(11—13) |
(10—13) |
(10—12) |
(12—14) |
(9.8—13.7) |
(11.7—14.7) |
(10.7—12.7) |
a
|
25.0±1.3 |
26.5±0.9 |
25.0±1.4 |
23.1±0.8 |
24±0.84 |
25.6±1.04 |
27.4±1.8 |
(22.3—27) |
(24.9—28.8) |
(22.9—28) |
(21.4—24.1) |
(23.1—25.7) |
(24.1—27.5) |
(25.2—30.3) |
b
|
3.7±0.2 |
3.6±0.1 |
3.4±0.1 |
4.3±0.5 |
3.4±0.16 |
3.8±0.19 |
3.8±0.17 |
(3.2—4.3) |
(3.4—4) |
(3.1—3.8) |
(3.3—4.9) |
(3.1—3.7) |
(3.4—4.1) |
(3.6—4.1) |
c
|
22.9±2.1 |
23.8±1.2 |
24.2±1.7 |
22.5±1.6 |
21.9±0.34 |
21.4±0.85 |
25.3±2.0 |
(17—25.3) |
(21.2—26.5) |
(21.1—27.8) |
(21.4—26.7) |
(21.7—22.7) |
(19.7—22.8) |
(21.4—29.4) |
c`
|
1.5±0.1 |
1.6±0.1 |
1.5±0.1 |
1.3±0.1 |
1.6±0.06 |
1.7±0.10 |
1.5±0.19 |
(1.3—2) |
(1.5—2) |
(1.3—1.8) |
(1.2—1.5) |
(1.5—1.7) |
(1.5—1.8) |
(1.3—1.8) |
V |
40±1.5 |
39.8±1.1 |
40.6±0.8 |
37.9±1.7 |
41.3±1.3 |
39.3±1.2 |
42.3±2.8 |
(37.6—43) |
(38.2—42.5) |
(38—41.9) |
(35.6—42) |
(39.2—43.6) |
(36.9—41.1) |
(39.05—48.1) |
G1 |
0.9±0.1 |
0.7±0.1 |
1.0±0.1 |
1.0±0.1 |
1.2±0.22 |
1.1±0.24 |
1.4±0.14 |
(0.8—1.1) |
(0.6—1) |
(0.7—1.2) |
(0.9—1.2) |
(1.06—1.6) |
(0.85—1.7) |
(1.1—1.6) |
G2 |
19.9±3.3 |
22.3±2.0 |
23.5±1.1 |
22.7±3.3 |
23.7±1.5 |
22.4±2.1 |
21.5±1 |
(14.8—24.2) |
(17.3—24.8) |
(21.2—25.7) |
(17.2—27.8) |
(21.9—26.4) |
(18.4—26.4) |
(19.9—23) |
Lip region diameter |
5.0±0.1 |
5.0±0.1 |
4.8±0.3 |
5±0 |
4.6±0.37 |
4.9 |
4.9±0.19 |
(5—5.5) |
(5—5.5) |
(4—5) |
(5—5) |
(3.9—4.9) |
(4.9—5.3) |
Lip region height |
2.3±0.3 |
2.3±0.3 |
2.1±0.2 |
2.2±0.3 |
2.4±0.28 |
2.6±0.43 |
2.2±0.24 |
(2—3) |
(2—3) |
(2—2.5) |
(2—3) |
(1.9—2.9) |
(1.6—2.5) |
(1.9—2.4) |
Amphid aperture |
3.1±0.2 |
2.8±0.3 |
3.1±0.5 |
2.4±0.3 |
3.02±0.2 |
3.3±0.51 |
2.9 |
(2.5—3.5) |
(2—3) |
(2.5—4) |
(2—3) |
(2.9—3.4) |
(2.9—4.4) |
……continued on the next page
TABLE].
(Continued)
Characters
|
Dachigam
|
Baramullah
|
Kangan Valley
|
Kigwema,
|
Gudalur,
|
Ooty,
|
German population
|
National Park
|
(Kashmir)
|
(Kashmir)
|
Nagaland
|
Tamil Nadu
|
Tamil Nadu
|
(Kashmir)
|
population
|
population
|
population
|
population
|
population
|
population
|
Females
|
Females
|
Females
|
Females
|
Females
|
Females
|
Females
|
Odontostyle length |
4.8±0.4 |
4.2±0.4 |
4.0±0.4 |
4.6±0.4 |
4.4±0.33 |
4.4±0.37 |
5.1±0.39 |
(4—5.5) |
(4—5) |
(4—5) |
(4—5) |
(4—5) |
(4—5) |
(4.9—5.8) |
Odontophore length |
8.2±0.4 |
8.3±0.4 |
8.2±0.4 |
6.4±0.4 |
8.1±0.23 |
7.4±0.45 |
7.5±0.45 |
(8—9) |
(8—9) |
(8—9) |
(6—7) |
(7.8—8.3) |
(6.8—7.8) |
(6.8—8.3) |
Guiding ring from anterior |
4.7±0.4 |
4.1±0.7 |
4.3±0.7 |
3±0 |
3.6±0.24 |
4.2±0.61 |
4.3±0.29 |
end |
(4—5) |
(3—5) |
(3—5) |
(3—3) |
(3.4—3.9) |
(3.4—4.9) |
(3.9—4.9) |
Nerve ring from anterior |
57.0±2.4 |
58.1±2.3 |
53.5±3.2 |
47.8±2.8 |
53.5±2.5 |
56.9±3.1 |
56.1±2.4 |
end |
(53—61) |
(55—60) |
(48—60) |
(44—53) |
(50.9—58.8) |
(49—59.7) |
(53.9—60.7) |
Neck length |
120±5.2 |
122.7±3.9 |
118±6.2 |
93.8±10.1 |
120.7±3.4 |
121.2±4.6 |
118.6±7.4 |
(112—129) |
(116—133) |
(102—127) |
(86—117) |
(114.6—125.4) |
(113.6—131.3) |
(107.8—129.3) |
Expanded part of pharynx |
28.8±1.9 |
31±1.3 |
29.6±1.6 |
24.7±1.6 |
31.6±1.3 |
29.4±2.1 |
29.8±0.90 |
(25—32) |
(29—34) |
(25—32) |
(23—28) |
(29.4—33.2) |
(23.5—31.3) |
(28.4—31.3) |
Cardia length |
4.3±0.6 |
4.4±0.7 |
4.2±0.7 |
3.1±1.0 |
3.6±0.37 |
4.4±0.68 |
4.3±0.40 |
(3—5) |
(3—5) |
(3—5) |
(2—5) |
(2.9—3.9) |
(3.9—5.8) |
(3.9—4.9) |
Anterior genital branch |
4.2±0.4 |
3.8±0.6 |
4.7±0.6 |
4.7±0.7 |
5.3±0.5 |
5.3±1.09 |
6.7±0.53 |
(4—5) |
(3—5) |
(3.5—5) |
(4—5.5) |
(4.9—5.8) |
(3.9—7.8) |
(5.8—7.8) |
Posterior genital branch |
90.5±15.1 |
102.8±10.0 |
97.9±7.6 |
93.2±15.6 |
101.2±6.05 |
103.3±7.3 |
101.1±9.8 |
(65—115) |
(82—117) |
(86—114) |
(65—121) |
(93.1—112.7) |
(91.1—112.7) |
(86.2—120.5) |
Vaginal length |
10±0.5 |
9.6±0.4 |
9.6±0.4 |
9±0.8 |
9.1±0.46 |
9.6±0.63 |
9.3±0.65 |
(9—11) |
(9—10) |
(9—10) |
(8—10) |
(8.8—9.8) |
(8.8—10.7) |
(8.8—10.7) |
Vulva from anterior end |
181.0±12.3 |
183.2±8.0 |
168.7±9.7 |
154.5±7.5 |
173.2±8.8 |
181.5±9.5 |
193.9±19.07 |
(168—208) |
(162—195) |
(154—187) |
(140—164) |
(157.7—186.2) |
(168.5—206.7) |
(165.6—223.4) |
Prerectum length |
40.7±4.3 |
42.6±5.9 |
44.3±6.3 |
33.5±0.5 |
33.3±5.15 |
37.6±3.5 |
40.8±5.06 |
(36—50) |
(35—52) |
(33—59) |
(33—34) |
(23.5—41.1) |
(31.3—45.08) |
(33.3—49) |
Rectum length |
10.4±0.9 |
10.8±1.1 |
10.5±0.9 |
10.4±1.0 |
11.2±1.2 |
13.4±2.1 |
12.8±0.92 |
(9—12) |
(9—13) |
(9—12) |
(9—12) |
(9.8—13.7) |
(10.7—19.6) |
(11.7—14.7) |
Tail length |
19.8±2.3 |
19.3±1.3 |
17.1±1.1 |
18.1±1.0 |
19.1±1.4 |
21.5±1.3 |
18.1±1.4 |
(18—25) |
(16—22) |
(15—19) |
(16—20) |
(16.6—20.5) |
(18.6—24.5) |
(15.6—19.6) |
Remarks.
Jairajpuri (1963) described
Doryllium minor
from Srinagar, Kashmir,
India
.
Goseco
et al.
(1975)
redescribed this species based on a study of the
holotype
as well as additional material from
Indiana
.
Goseco
et al
. (1981)
further redescribed this species from
Panama
while
Nasira
et al
. (2005)
redescribed it from
Pakistan
. The present specimens, collected from three entirely different geographical areas in
India
, as well as a population from
Germany
provide a much wider range of morphometric data on this widely distributed species. Interestingly, the morphometric data of all seven of these populations are quite similar without any significant differences; however, some morphological differences were recorded. The three populations from Kashmir valley, the region from where the
type
population was collected fits well with the original morphometric data provided by Jairajpuri (1963). However, the amphid is rather cup-shaped in the Dachigam National Park and Kangana valley populations, whereas it is stirrup-shaped in the Baramullah population. The outer cuticle is smooth in all three Kashmir populations as well as in the
Nagaland
population. Jairajpuri (1963) and
Goseco
et al
. (1975)
described outer cuticle as smooth. The
Nagaland
population also has a cup-shaped amphid. The two populations from
Tamil Nadu
, as well as the German population, have a distinctly striated outer cuticle and cup-shaped amphid. The tail in the Gudalur,
Tamil Nadu
population is similar to that of the
type
population, whereas it is rather more clavate in the Ooty population as well as in the German population. None of these morphological differences show a definite combination of characters, hence it is concluded that these differences are simple geographical variations and one has to be very cautious when using these characters individually when differentiating species.
Two
Doryllium
species,
D. cornelli
(van der
Linde, 1938
) Jairajpuri & Siddiqi, 1963
and
D. coronatum
Brzeski, 1962
are very close to
D. minor
, however,
D. cornelli
is characterized by its distinctly sclerotized stoma lining and odontophore almost equal in length to odontostyle.
D. coronatum
is distinctive in having domed, projecting liplets around oral opening and odontophore about three times as long as odontostyle.