Four new Paramphimonhystrella species (Nematoda: Xyalidae) from the continental slope of New Zealand
Author
Leduc, Daniel
text
Zootaxa
2014
3814
4
478
494
journal article
45523
10.11646/zootaxa.3814.4.2
1f0c9e98-3d8e-4c08-8b80-2e375bfaf6fe
1175-5326
231397
84CD1F7F-9E65-48F3-BE24-C8815264671A
Paramphimonhystrella barbula
n. sp.
(
Figs 5
and
6
,
Table 1
)
Type
specimens.
Holotype
male (
NIWA
89974), collected on
15 April 2010
(
NIWA
cruise TAN1004, station 4), open slope habitat on southern Hikurangi Margin (
175.6642ºE
,
41.6837ºS
); water depth:
1046 m
. One
paratype
male (
NNCNZ
3165), same data as
holotype
. Two
paratype
males (
NIWA
89975), collected on
21 April 2010
(
NIWA
cruise TAN1004, station 72), open slope habitat on southern Hikurangi Margin (
176.1958ºE
,
41.3657ºS
); water depth:
985 m
.
One
paratype
male (
NNCNZ
3166), collected on
22 April 2010
(
NIWA
cruise TAN1004, station 76), open slope habitat on southern Hikurangi Margin (
175.6500ºE
,
41.6833ºS
); water depth:
1282 m
. One
paratype
female (
NIWA
89976), collected on
5 October 2001
(
NIWA
cruise TAN0116, station U2582), Chatham Rise crest (
178.5000ºE
,
43.4333ºS
); water depth:
350 m
; silt/clay content: 37.5%; CaCO3 content: 61.6%.
Etymology.
The species name is the diminutive of the latin word
barba
(= beard) and refers to the relatively short sub-cephalic setae in this species.
FIGURE 5.
Paramphimonhystrella barbula
A: Lateral surface view of male head; B: lateral view of male head; C: lateral view of female head; D: male anterior body region; E: female anterior body region; F: female posterior body region; G: male posterior body region; H: sperm. Scale bar: A–C, F–H = 20 µm; D and E = 27 µm.
FIGURE 6.
Paramphimonhystrella barbula
A: Entire male; B: entire female. Scale bar = 50 µm.
TABLE 1
. Morphometrics (µm) of
Paramphimonhystrella glossalga
n. sp.
and
P. barbula
n. sp.
(a, body length/maximum body diameter; abd, anal body diameter; b, body length/pharynx length; c, body length/tail length; cbd, corresponding body diameter; V, vulva distance from anterior end of body; %V, V/total body length).
Species
P.
glossalga
n. sp.
P. barbula
n. sp.
Males Females Males Female
Holotype
Paratype Paratypes
Holotype
Paratypes Paratype
n 1 3 4 1 L 1402 1376
1012-1309
991 958-1086 1117
Description.
Males
. Body cylindrical, tapering slightly towards anterior extremity. Cuticle ~0.6–0.8 µm thick, with fine striations ~1 µm apart beginning immediately anterior to amphids (
Figure 5
A). Somatic setae short and sparse, irregularly arranged. Head tapering anteriorly or with depression just anterior to amphids. Inner labial sensillae not observed; six outer labial setae, 2–3 µm long, situated immediately anterior to four cephalic setae of same length. Two rings of sub-cephalic setae; anterior ring consists of ten 3–6 µm long setae at level of amphids dorsally and ventrally and slightly posterior to amphids laterally; second ring consists of ten setae of same length situated 0.5–1.0 cbd posterior to first ring of sub-cephalic setae (
Figure 5
A–E). Amphids large, with oval or ovoid outline, lightly cuticularised. Buccal cavity 9–11 µm deep, 1–2 µm wide, with cylindrical anterior portion and funnel-shaped posterior portion, lightly cuticularised; posterior portion surrounded by pharyngeal tissue. Pharynx muscular, widening posteriorly but not forming true bulb. Cardia elongated, with posterior end surrounded by intestine tissue and a pair of gland-like cells dorsally and ventrally (
Figure 5
D, E). Nerve situated at middle of pharynx. Secretory-excretory system not observed.
| a |
37 |
33 |
30-33 |
55 |
51-54 |
45 |
| b |
6 |
6 |
6 |
7 |
6-7 |
7 |
| c |
5 |
5 |
5 |
7 |
6-7 |
6 |
| Head diam.* |
18 |
15 |
10-13 |
3 |
3-4 |
5 |
| Buccal cavity length |
28 |
31 |
19-26 |
9 |
8-12 |
8 |
| Buccal cavity width Length of sub-cephalic setae1st circle Length of sub-cephalic setae 2nd circle |
11 4-9 22-24 |
11 6-9 13-20 |
7-9 4-13 13-25 |
1 3-6 3-6 |
1-2 4-6 4-6 |
2 5 5 |
| Length of cephalic setae |
7 |
8 |
6-7 |
2 |
2-3 |
3 |
| Amphid height |
15 |
15 |
8-10 |
10 |
9-14 |
7 |
| Amphid width |
13 |
12 |
7-9 |
6 |
6-8 |
5 |
| Amphid width/cbd (%) |
57 |
46 |
39-45 |
60 |
60-66 |
56 |
| Amphid from anterior end |
20 |
23 |
15-20 |
10 |
8-10 |
10 |
| Nerve ring from anterior end |
115 |
122 |
178-219 |
74 |
80-83 |
81 |
| Nerve ring cbd |
36 |
41 |
29-39 |
17 |
18-19 |
19 |
| Pharynx length |
217 |
222 |
178-219 |
152 |
148-172 |
153 |
| Pharynx diameter at base |
19 |
25 |
21-24 |
7 |
9-13 |
8 |
| Pharynx cbd (at base) |
37 |
39 |
29-39 |
16 |
18-20 |
19 |
| Max. body diam. |
38 |
42 |
31-43 |
18 |
18-21 |
25 |
| Spicule length |
30 |
34 |
- |
63 |
43-62 |
- |
| Gubernacular apophyses length |
- |
- |
- |
14 |
11-14 |
- |
| Anal body diam. |
31 |
30 |
21-30 |
18 |
16-19 |
17 |
| Tail length |
289 |
273 |
201-279 |
149 |
139-171 |
174 |
| Tail length/abd |
9.3 |
9.1 |
9.3-9.8 |
8.3 |
8.2-10.7 |
10.2 |
| V |
- |
- |
534-630 |
- |
- |
587 |
| %V |
- |
- |
47-53 |
- |
- |
53 |
| Vulval body diam. |
- |
- |
29-41 |
- |
- |
21 |
| *At level of cephalic setae |
Male reproductive system diorchic with outstretched testes; in some specimens only the anterior or posterior testis is visible. Both testes (when observed) situated to the right of intestine. Mature sperm cells small and rodshaped, ~1×6 µm (
Figure 5
H). Spicules slender, 2.7–3.6 abd long, lightly cuticularised, with blunt proximal end and pointed distal end (
Figure 5
G); gubernaculum present, thin, parallel to spicules, with fine lateral crurae. Precloacal supplements absent. Tail conico-cylindrical, with one pair of sub-ventral and one pair of sub-dorsal setae ~2 cbd posterior to cloaca and single dorsal seta on cylindrical portion. Two terminal setae, 7–10 µm long. Three caudal gland; one gland conspicuously larger than other two and giving tail a swollen appearance (
Figure 5
G and 6A).
TABLE 2
. Morphometrics (µm) of
Paramphimonhystrella scutula
n. sp.
and
P. echinocauda
n. sp.
(a, body length/maximum body diameter; abd, anal body diameter; b, body length/pharynx length; c, body length/tail length; cbd, corresponding body diameter; V, vulva distance from anterior end of body; %V, V/total body length).
Species
P. scutula
n. sp.
P. echinocauda
n. sp.
Males Females Males
Holotype
Paratype Paratypes
Holotype
Female
. Similar to males, but with slightly smaller amphids. Reproductive system monodelphic with outstretched anterior branch to the left of intestine; postvulvar sac present, consisting of numerous clear cells; sperm cells observed in uterus but not postvulvar sac (
Figure 6
B). Mature egg 118×19 µm. Vulva situated mid-body. Granular vaginal glands not observed; pars proximalis vaginae surrounded by constrictor muscle.
| n |
- |
1 |
2 |
- |
| L |
891 |
890 |
927, 947 |
965 |
| a |
50 |
56 |
46, 53 |
57 |
| b |
6 |
6 |
6 |
6 |
| c |
7 |
7 |
7 |
8 |
| Head diam.* |
4 |
5 |
5 |
7 |
| Buccal cavity length |
12 |
12 |
13, 14 |
7 |
| Buccal cavity width Length of sub-cephalic setae1st circle Length of sub-cephalic setae 2nd circle |
3 1 6 |
2 1 6-7 |
3 1 6 |
4 2 7 |
| Length of cephalic setae |
3 |
4 |
3, 4 |
2 |
| Amphid height |
7 |
6 |
5 |
6 |
| Amphid width |
5 |
6 |
5 |
6 |
| Amphid width/cbd (%) |
42 |
50 |
38, 42 |
50 |
| Amphid from anterior end |
13 |
14 |
12, 14 |
10 |
| Nerve ring from anterior end |
80 |
75 |
71, 84 |
68 |
| Nerve ring cbd |
16 |
16 |
17 |
16 |
| Pharynx length |
152 |
141 |
147, 154 |
156 |
| Pharynx diameter at base |
10 |
10 |
10, 11 |
11 |
| Pharynx cbd (at base) |
17 |
16 |
17 |
16 |
| Max. body diam. |
18 |
16 |
18, 20 |
17 |
| Spicule length |
21 |
21 |
- |
27 |
| Gubernacular apophyses length |
- |
- |
- |
11 |
| Anal body diam. |
14 |
15 |
15 |
15 |
| Tail length |
134 |
128 |
127, 129 |
114 |
| Tail length/abd |
9.6 |
8.5 |
8.5, 8.6 |
7.6 |
| V |
- |
- |
554, 587 |
- |
| %V |
- |
- |
60, 62 |
- |
| Vulval body diam. |
- |
- |
18, 20 |
- |
| *At level of cephalic setae |
Diagnosis.
Paramphimonhystrella barbula
n. sp.
is characterised by narrow buccal cavity with funnel shaped posterior portion, oval-shaped amphids, two rings of ten sub-cephalic setae, conico-cylindrical tail with swollen appearance due to conspicuously enlarged caudal gland, and males with long slender spicules and small gubernaculum parallel to the spicules.
Differential diagnosis.
Paramphimonhystrella barbula
n. sp.
is similar to
P. elegans
in the shape of the buccal cavity, size and shape of the amphids, number and arrangement of sub-cephalic setae, and shape of the tail. It differs from the latter in body size (991–1117 µm in
P. barbula
n. sp.
vs
1286–1916
µm in
P. elegans
), length of cephalic setae (2–3 vs 4–6 µm), length of the spicules (2.7–3.6 vs 0.7–1.0 abd), and presence of gubernaculum (vs absent).