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 brachyrhynchus
(
Fowler, 1934
)
Figs. 2
A–B;
Tables 1–2
Arisoma
[sic]
brachyrhynchus
Fowler, 1934
:269
(Utara Pt., Bongo
Island
, Illana Bay, southern Mindanao
Island
,
Philippines
,
7°21’45”N
,
124°07’15”E
, depth 158 fathoms [
289 m
]).
Parabathymyrus brachyrhynchus
(
Fowler, 1934
)
:
Smith & Kanazawa, 1977
:532
.
Smith, 1989
:504
.
Smith, 1999
:1686
.
Iwamoto & McCosker, 2014
:272
.
Parabathymyrus macrophthalmus
(not of
Kamohara, 1938
):
Chen & Weng, 1967
:175
.
Shen, 1984
:111
.
Chen & Yu, 1986
:252
.
Shen
et al.
1993
:117
.
Shen & Wu, 2011
:139
.
Material examined
(47, 186–
502 mm
TL).
Holotype
:
USNM
92357 (1, 327), Southern Mindanao, Eastern Illana Bay, Utara Point, Bongo
Island
,
Philippines
,
7°21'45"N
,
124°07'15"E
,
289 m
,
22 May 1908
.
Paratype
:
USNM
135121 (1, 268), Gulf of Davao, Dumalag
Island
,
7°02'N
,
125°38'4"E
,
247 m
,
18 May 1908
, Albatross D.5247.
Non-types
:
Taiwan
: off Dong-gang, SW
Taiwan
, ca.
150–350 m
:
ASIZP
65130 (1, 383),
10 Mar. 2005
.
CSIRO
H7398-12 (1, 457),
18 Mar. 2012
.
CSIRO
H7419-07 (1, 376),
27 Dec. 2012
. NMMB-P 1403 (1, 470),
4 Mar. 1965
. NMMB-P 1412 (1, 405),
6 Feb. 1966
. NMMB-P 2458 (1, 328), no date. NMMB-P 9079 (1, 430),
13 Jun. 2008
. NMMB-P 9092 (1, 470),
13 Jun. 2008
. NMMB-P 11167 (1, 345),
15 Dec. 2009
. NMMB-P 11168 (1, 466),
15 Dec. 2009
. NMMB-P 11169 (1, 424),
15 Dec. 2009
. NMMB-P 11914 (3, 402–472),
26 Feb. 2011
. NMMB-P 12175 (1, 428),
31 Dec. 2010
. NMMB-P 13161 (1, 502),
12 Sep. 2009
. NMMB-P 13674 (1, 351),
2 Jul. 2011
. NMMB-P 14034 (1, 355),
3 Nov. 2011
. NMMB-P 15391 (1, 420), no date. NMMB-P 15566 (1, 383), no date. NMMB-P 16437 (1, 407),
15 Jun. 2009
. NMMB-P 17791 (1, 464),
9 Aug. 2012
. NMMB-P 17868 (1, 392),
25 Jan. 2012
. NMMB-P 17869 (1, 342),
25 Jan. 2012
.
USNM
398510 (1, 395),
12 Nov. 2009
.
USNM
400284 (1, 410),
25 May. 2010
.
USNM
395265 (1, 483),
16 May. 2008
. Off Daxi, NE
Taiwan
: NMMB-P 15565 (2 of 3, 385–387),
23 Oct. 2011
. Off Nan-fang-ao, Yilan, NE
Taiwan
: NMMB-P16195 (1, 317),
20 Jul. 2010
.
The
Philippines
:
USNM
344105 (6, 320–364), Albay Gulf, Luzon,
Philippines
,
363–385 m
,
23 Sep. 1995
.
Vietnam
: NMMB-P 12330 (1, 361), Da Nang,
9 Apr. 2011
.
Vanuatu
:
MNHN
1997-0827 (3, 379–448),
15°7'1.2"S
,
166°55'1.2"E
,
262–352 m
,
9 Sep. 1994
.
Solomon Islands
:
MNHN
2002-3850 (6, 186–340),
9° 21'3.6"S
,
160°23'13.2"E
,
357–359 m
,
1 Oct. 2001
.
MNHN
2006-0079 (1, 343),
7°28'15.6"S
,
156°18'25.2" E
,
105 m
,
2 Nov. 2004
.
FIGURE 2.
Parabathymyrus brachyrhynchus
(Fowler, 1934)
. A. NMMB-P 12175, 428 mm TL. NMMB-P 11914, 1 of 3, 402 mm TL. Both collected from Dong-gang, SW Taiwan.
TABLE 2.
Meristic data of three
Parabathymyrus
species examined in this study. Abbreviations: PreD=predorsal; PreA =preanal; PreP=prepectoral; V=vertebrae.
P. philippinensis
sp. nov.
P. brachyrhynchus
P. macrophthalmus
MVF 8-42-142 11-52-164 10-43-133
Holotype |
Paratype |
Holotype Taiwan (n=28) |
Others (n=19) |
Japan (n=5) |
Taiwan (n=32) |
Vietnam (n=14) |
PreD-V |
8 |
8 |
19 8–13 |
10–11 |
-- |
9–13 [15]* |
10–11 |
PreA-V |
42 |
42 |
55 49–52 |
49–58 |
-- |
39–46 |
42–45 |
Total-V |
141 |
142 |
166 162–173 |
162–169 |
-- |
128–137 |
129–135 |
P fin rays |
14 |
14 |
-- |
14–17 |
-- |
14–15 |
12–17 |
13–16 |
PreP pores |
8 |
8 |
-- |
7–9 |
8–10 |
7 |
5–9 |
6–8 |
PreD pores |
10 |
8 |
-- |
8–10 |
8–11 |
8–10 |
6–11 [12]* |
8–10 |
PreA pores |
40 |
42 |
49 |
48–52 |
46–54 |
39–41 |
36–44 |
37–43 |
Total pores |
140 |
141 |
-- |
159–163 |
158–169 |
127–130 |
121–132 |
123–130 |
SO pores |
3 |
3 |
4 |
4 |
4 |
4 |
4 |
4 |
IO pores |
5 |
5 |
5 |
5 |
5 |
5 |
5 |
5 |
POM pores |
11 |
11 |
11 |
10–12 |
10–11 |
9–11 |
10–12 |
9–11 |
ST pore |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
F pore |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
AD pore |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
*Value of NMMB-P 11170.
Diagnosis.
A species of
Parabathymyrus
with 4 supraorbital pores; head
5.5–6.7 in
TL; 49–58 preanal vertebrae; 162–173 total vertebrae; 48–54 preanal LL pores; 159–169 total LL pores. Two rows of teeth on most of both jaws.
Description.
Head length 5.5–6.7 times in TL; body depth at head 13.4–16.9; predorsal 4.9–6.4; preanal 2.3– 2.6; trunk length 3.6–4.4; tail length 1.6–1.8. Snout 5.4–7.6 times in HL; eye 4.8–6.5; interorbital 4.7–12.5; snoutrictus 2.9–4.2; gill opening 5.5–8.1; interbranchial 3.7–6.4; pectoral fin 2.1–3.4. Pectoral-fin rays 14–17.
Body relatively stout, depth of head not much larger than that of tail; head and trunk cylindrical, gradually compressed to caudal fin; 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 and its posterior margin slightly behind level of rictus; interorbital space broad; gill opening moderately high, in front of pectoral fin and extended to middle of pectoralfin base. Anterior nostril tube-like, at front of snout; posterior nostril large, just above the upper jaw, covered by a large flap dorsally.
Mouth moderately large, its opening slightly oblique, rictus extends 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.
Teeth small and villiform; intermaxilla with 4 rows of teeth forming a rounded patch, exposed when mouth closed; vomerine teeth a small triangular patch closely attached to that of intermaxilla; both jaws with 4–6 rows of teeth on anterior part and 1–2 rows on most of the remainder.
Vertebrae: predorsal 8–13, preanal 49–58, total 158–173 and mean vertebral formula (MVF) 11-52-164. Lateral-line pores moderate in size and complete, prepectoral 7–10, predorsal 8–11, preanal 46–54 and total 158– 169. Head pores: SO 4, IO 5, POM 10–12, ST 0, F 0, AD 0.
Coloration.
When fresh, pinkish brown or yellowish brown dorsally, paler ventrally, pectoral fins reddish to grayish, anterior part of median fins yellowish or pinkish, with black margin in posterior portion. When preserved, brownish gray dorsally and paler ventrally, pectoral fin white, anterior part of median fins pale, with black margins in posterior portion, mouth cavity, gill chamber and peritoneum white.
Distribution.
Known only from the western Pacific off
Taiwan
,
Vietnam
, the
Philippines
,
Vanuatu
and
Solomon Islands
. Bathymetric range
105–
385 m
.
Remarks.
Smith (1994)
reported 19 predorsal vertebrae for the
holotype
of
P. brachyrhynchus
, whereas all specimens we examined have 8–13 (n=38) predorsal vertebrae. We also found a specimen of
P. macrophthalmus
that has relatively more predorsal vertebrae (15, vs.
9–13 in
other specimens, n=46). The relatively more predorsal vertebrae in these specimens of
P. brachyrhynchus
and
P. macrophthalmus
is apparently anomalous.
Karmovskaya (2004)
separated
P. fijiensis
from
P. brachyrhynchus
by having relatively more total vertebrae (173 vs. 166–168), fewer preanal pores (47 vs. 50–52), and its dorsal-fin origin above the pectoral-fin base (vs. dorsal-fin origin slightly behind middle of pectoral fin). The
holotype
of
P. fijiensis
has 50 preanal pores and 167 total pores (HH's examination). We also examined a large number of
P. brachyrhynchus
and found that the data for the
holotype
of
P. fijiensis
mostly fall within the range of
P. brachyrhynchus
(
Tables 1–2
). More specimens of
P. fijiensis
are needed to understand the variation of this species and whether it and
P. brachyrhynchus
are conspecific.
HH examined three specimens from
Vanuatu
and seven specimens from the
Solomon Islands
. All these specimens are identical to those of
P. brachyrhynchus
that we examined. Thus they are identified as
P. brachyrhynchus
rather than
P. fijiensis
.
It is also notable that the
holotype
of
P. fijiensis
does not have a black anal-fin margin, whereas all specimens of
P. brachyrhynchus
have a black margin on their anal fin and those from
Vanuatu
and the Solomons have a slightly broader black margin than those from the NW Pacific Ocean.