Notes on the congrid eel genus Parabathymyrus from the western Pacific Ocean, with the description of a new species (Pisces: Anguilliformes: Congridae)
Author
Ho, Hsuan-Ching
Author
Smith, David G.
Author
Shao, Kwang-Tsao
text
Zootaxa
2015
4060
1
131
139
journal article
39197
10.11646/zootaxa.4060.1.15
ec9c104d-1ae5-4ee1-aa7b-43260f8ef9c6
1175-5326
241255
60B7E365-6B44-41DA-87DC-4C78E2E02C3C
Parabathymyrus philippinensis
sp. nov.
Figs. 1
A–C;
Tables 1–2
Holotype
.
ASIZP
68112 (398),
14.54°N
,
121.7°E
, off Aurora, Luzon,
Philippines
,
233–249 m
,
29 May 2007
.
Paratype
.
ASIZP
68117 (1, 341),
16.51°N
,
122.01°E
, off Aurora, Luzon,
Philippines
,
335–356 m
,
28 May 2007
.
FIGURE 1.
Parabathymyrus philippinensis
sp. nov.
A, B. Holotype, ASIZP 68112, 398 mm TL. C. Paratype, ASIZP 68117, 341 mm TL. Both from Aurora, Luzon, Philippines. A, C photo by Y.-C. Liao.
Diagnosis.
A species of
Parabathymyrus
with head
5.6–5.7 in
TL; 3 supraorbital pores; 42 preanal vertebrae; 141–142 total vertebrae; 40– 42 preanal lateral-line (LL) pores; 140–141 total LL pores.
Description.
Head length 5.7 (
5.6 in
paratype
) times in TL; body depth at head 16.2 (12.7); predorsal 5.7 (5.2); preanal 2.4 (2.5); trunk length 4.2 (4.8); tail length 1.7. Snout 6.6 (5.8) times in HL; eye 5.8 (4.7); interorbital 9.8 (8.2); snout-rictus 3.2 (3.1); gill opening 9.6 (5.8); interbranchial 3.8 (3.4); pectoral fin 2.5 (2.8). Pectoral-fin rays 14.
TABLE 1.
Morphometric data of three
Parabathymyrus
species examined in this study.
P. philippinensis
sp. nov.
P.brachyrhynchus
P.macrophthalmus
Value of NMMB-P 11170.
| Holotype |
Paratype |
Holotype |
Taiwan |
Philippines |
Vanuatu |
Japan (n=5) |
Taiwan (n=22) |
Vietnam (n=13) |
| TL (mm) |
398 |
341 |
327 |
317–505 (n=29) |
268–480 (n=9) |
379–448 (n=3) |
275–405 |
260–417 |
226–386 |
| %TL |
| Head length |
17.5 |
17.9 |
17.1 |
16.3 (15.0–18.1) |
17.1 (16.6–18.0) |
16.1 (15.4–16.5) |
15.0 (14.7–15.2) |
16.1 (14.7–17.1) |
16.4 (15.4–17.3) |
| Trunk length |
23.7 |
20.9 |
26.0 |
24.7 (23.0–26.3) |
24.9 (22.6–27.5) |
24.6 (23.9–25.3) |
23.9 (23.0–24.8) |
23.9 (21.5–25.6) |
24.2 (21.8–26.2) |
| Tail length |
58.8 |
59.8 |
56.9 |
58.9 (57.2–61.8) |
58.0 (55.9–59.7) |
59.3 (58.9–59.6) |
60.5 (59.3–62.2) |
60.0 (58.4–63.4) |
60.1 (57.7–70.8) |
| Predorsal |
17.5 |
19.3 |
20.4 |
17.1 (15.7–18.9) |
17.7 (16.6–20.4) |
16.6 (16.3–17.1) |
17.1 (15.9–17.6) |
17.1 (16.1–18.6) [21.1]* |
17.9 (16.5–20.0) |
| Preanal |
41.2 |
40.2 |
43.1 |
41.1 (38.2–42.8) |
42.0 (40.3–44.1) |
40.7 (40.4–41.1) |
39.1 (38.3–40.0) |
40.0 (36.6–41.6) |
40.5 (37.4–42.3) |
| Depth at anus |
6.2 |
6.3 |
6.7 |
6.0 (4.4–7.6) |
6.1 (4.9–7.2) |
5.2 (5.0–5.5) |
-- |
6.1 (4.9–7.6) |
5.8 (4.7–6.8) |
| %HL |
| Eye diameter |
17.2 |
21.3 |
16.1 |
17.5 (15.3–20.7) |
17.0 (16.1–18.3) |
20.4 (18.8–22.4) |
18.2 (17.1–20.1) |
16.2 (12.8–18.1) |
16.0 (14.0–17.6) |
| Interorbital |
10.2 |
12.1 |
8.6 |
16.8 (13.6–21.2) |
11.1 (8.0–16.2) |
17.7 (16.0–17.9) |
18.8 (16.6–19.8) |
17.7 (12.4–22.2) |
16.9 (13.4–20.2) |
| Snout length |
15.0 |
17.2 |
15.7 |
16.5 (13.2–18.6) |
15.8 (14.6–17.2) |
17.9 (17.1–19.2) |
17.5 (16.2–18.1) |
15.6 (12.9–18.2) |
16.8 (13.7–19.3) |
| Interbranchial |
26.6 |
29.2 |
20.9 |
23.0 (19.7–27.2) |
18.7 (15.6–21.0) |
19.1 (18.4–19.9) |
-- |
21.4 (16.2–28.2) |
20.4 (13.8–24.2) |
| Upper jaw |
31.7 |
32.5 |
30.9 |
29.7 (25.4–34.9) |
27.1 (23.7–30.9) |
30.8 (30.0–32.0) |
32.0 (29.7–34.8) |
29.7 (26.1–33.4) |
30.3 (26.4–34.2) |
| Postorbital |
67.8 |
61.5 |
68.2 |
67.7 (63.3–72.9) |
67.2 (64.5–69.1) |
66.4 (65.4–68.2) |
71.2 (69.4–73.2) |
68.2 (65.9–70.2) |
69.4 (65.8–73.4) |
| Gill opening |
10.5 |
17.2 |
13.4 |
15.4 (12.3–18.3) |
13.9 (12.5–15.8) |
17.5 (15.7–19.6) |
17.1 (15.6–19.3) |
14.6 (10.6–21.3) |
14.3 (11.5–19.8) |
| Pectoral fin |
40.4 |
35.2 |
37.7 |
36.3 (29.6–39.8) |
36.8 (30.3–48.0) |
35.9 (34.9–37.2) |
38.5 (30.4–41.5) |
34.9 (25.0–41.2) |
38.6 (33.3–43.3) |
Body relatively stout, depth of head slightly larger than that of tail; head and trunk cylindrical, gradually compressed to posterior half of body; trunk long; tail moderately long. Origin of dorsal fin above pectoral fin; original of anal fin slightly anterior to middle of total length; snout short and obtuse.
Eye relatively large, above posterior half of upper jaw, its posterior margin extending beyond a vertical through rictus; interorbital space narrow. Gill opening moderately high, in front of pectoral fin and extending dorsally to middle of pectoral-fin base. Anterior nostril tube-like, at front of snout; posterior nostril large, just above upper jaw, covered by a large flap dorsally.
Mouth moderately large, its opening slightly oblique, rictus extending to posterior one-third of orbit; upper jaw protrudes anterior to lower jaw; upper labial flange well developed, extending from anterior nostril to two-thirds of upper-jaw length; lower jaw with a deep fold from tip to rictus; pectoral fin narrow and pointed.
Vertebrae: Predorsal 8 (8), preanal 42 (42), and total 142 (141). Lateral line complete, pores moderate in size, prepectoral 8 (8), predorsal 10 (8), Preanal 40 (42), and total 140 (141). Head pores: supraorbital 3 (3), only anterior pores present, 4th pore at dorsal-anterior corner of eye absent; infraorbital 5 (5), 1 between nostrils, 3 below eye and 1 behind rictus, none behind eye; preoperculomandibular (POM) 11 (11), 7 anterior to rictus, 4 behind rictus; supratemporal commissure (ST) 0, frontal (F) 0, adnasal (AD) 0.
Teeth small, villiform, 4–5 rows of teeth on intermaxilla forming a rounded patch, exposed when mouth closed; vomerine teeth connected to those of intermaxilla, forming a small triangular patch; 4–5 rows of teeth on both jaws anteriorly, gradually narrowing to biserial posteriorly.
Coloration. When fresh (
Fig. 1
A, C), light brownish dorsally and paler ventrally, anterior portion of head and lower jaw blackish, fins reddish, thin black margins on dorsal and anal fins. When preserved (
Fig. 1
B), body brownish, abdomen yellowish, fins pale, thin black margins on dorsal and anal fins.
Distribution.
Known only from the
type
series, collected off Aurora Province, east coast of Luzon,
Philippines
, at a depth of
233–
356 m
.
Etymology.
The specific name is derived from the
type
locality, the
Philippines
.
Remarks.
Parabathymyrus philippinensis
sp. nov.
differs from the other four congeners in having 3 supraorbital pores (vs. 4) and 141–142 total vertebrae (vs.
128–137 in
P. macrophthalmus
,
149–152 in
P. oregoni
,
162–173 in
P. brachyrhynchus
, and
173 in
P. fijiensis
).
Table 3
summarizes the selected characters of all known
Parabathymyrus
.