Research Article |
Corresponding author: Yoshiaki Kai ( kai.yoshiaki.4c@kyoto-u.ac.jp ) Academic editor: Sven Kullander
© 2018 Yoshiaki Kai, Ronald Fricke.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Kai Y, Fricke R (2018) Taxonomic review of the deep water flathead genus Parabembras with description of the new species Parabembras multisquamata from the western Pacific Ocean (Teleostei, Parabembridae). ZooKeys 740: 59-76. https://doi.org/10.3897/zookeys.740.21729
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Three valid species of Parabembras are recognized: P. curta, P. robinsoni, and the new species P. multisquamata. Parabembras robinsoni from the southwestern Indian Ocean (South Africa to Mozambique) is easily distinguishable from the other species in having eleven spines in the first dorsal fin, a distinct symphyseal knob on the lower jaw, two preocular spines, and a single lachrymal spine. Parabembras multisquamata from the southwestern Pacific (Vanuatu, Papua New Guinea) and the Philippines, and P. curta, known from the northwestern Pacific (southern Japan to South China Sea), are similar in sharing the absence of a symphyseal knob on the lower jaw, the presence of two lachrymal spines, and a single preocular spine, but the former is clearly distinguished from the latter in usually having 10 spines in the first dorsal fin (vs. eight or nine spines in P. curta), 9–11 supraocular spines (vs. 6–8 in P. curta), 40–44 pored lateral line scales (vs. 34–39 in P. curta), and the pectoral fin extending beyond the level of the anus (vs. not reaching to the level of the anus in P. curta).
New species, Parabembras curta , Parabembras multisquamata , Parabembras robinsoni , Papua New Guiana, Philippines, taxonomy, Vanuatu
The family Parabembridae, or deep water flatheads, comprises only two species, Parabembras curta (Temminck & Schlegel, 1843) from the northwestern Pacific Ocean, and P. robinsoni Regan, 1921, from the western Indian Ocean (
We examined four relatively recently collected (1980–2012) specimens of a species of Parabembras from the waters of Vanuatu, Papua New Guinea, and the Philippines. These specimens differ from the two currently known species of the family by the spines on the head, number of dorsal-fin spines and pored lateral line scales, and several proportional measurements, and are described herein as a new species of Parabembras. In addition, the two congeneric species P. curtus and P. robinsoni are redescribed, and a key to the species of Parabembras is presented.
Counts and measurements follow
The specimens examined in this study are deposited in the fish collections of the Natural History Museum, London (
Parabembras
Bleeker, 1874: 370;
Bembras curtus Temminck and Schlegel, 1843 by monotypy.
Body cylindrical, head somewhat depressed. Dorsal surface of head with spines only, tubercles absent. Ctenoid scales covering nape, postorbital, cheek, and opercular regions. Lower jaw projecting beyond upper jaw; dermal flap on posterior margin of maxillary. Two dorsal fins; first dorsal fin with 9 (rarely 8) to 11 spines; second dorsal fin with one spine and 8 or 9 soft rays. Anal fin with three robust spines and 5 soft rays. Pectoral fin without free rays. Pelvic fin with one spine and 5 soft rays, inserted below base of pectoral fin. Pored lateral line scales 34–44.
Bembras
curtus
Temminck & Schlegel, 1843: 42, pl. 16 (fig. 6–7), Nagasaki, Japan;
Parabembras
curtus
:
Parabembras
curta
:
Bembradium
roseum
(not of
Parabembras curta is distinguished from P. robinsoni in the absence of a symphyseal knob on the lower jaw (vs. distinct symphyseal knob in P. robinsoni), presence of a single preocular spine (vs. two preocular spines), and presence of two robust lachrymal spines (vs. a single robust lachrymal spine). It is further distinguished from P. multisquamata, in having 6–8 supraocular spines (vs. 9–11 supraocular spines in P. multisquamata); nine (rarely eight) spines in the first dorsal fin (vs. 10 spines); 34–39 pored lateral-line scales (vs. 40–44 pored lateral line scales).
Measurements are shown in Table
Parabembras curtus | P. robinsoni | P. multisquamus | ||||||
---|---|---|---|---|---|---|---|---|
n=23 | n=9 | Holotype | Paratypes (n=3) | |||||
Range | Mean | Range | Mean | Range | Mean | |||
Standard length (SL in mm) | 167.3 | 146.4–186.9 | ||||||
in % SL | ||||||||
Head length | 40.0–43.8 | 41.6 | 37.7–43.9 | 41.6 | 40.6 | 40.3–42.2 | 41.2 | |
Snout length | 9.7–11.0 | 10.4 | 10.4–12.4 | 11.2 | 10.6 | 10.1–10.7 | 10.4 | |
Orbit diameter | 11.3–14.2 | 12.5 | 11.7–14.1 | 12.6 | 12.0 | 12.3–13.9 | 13.0 | |
Body depth 1 | 16.0–20.6 | 18.2 | 14.7–18.6 | 17.1 | 16.9 | 17.9–19.8 | 18.7 | |
Body depth 2 | 15.2–18.1 | 16.6 | 13.6–16.2 | 14.8 | 16.1 | 16.5–17.4 | 17.0 | |
Body width | 15.9–19.6 | 17.8 | 13.9–18.8 | 16.2 | 15.1 | 14.6–16.8 | 15.8 | |
Caudal peduncle depth | 8.3–10.1 | 9.1 | 7.6–8.9 | 8.1 | 9.6 | 9.6–10.4 | 10.0 | |
Upper jaw length | 13.9–15.9 | 15.1 | 15.8–18.3 | 16.6 | 15.2 | 15.7–16.5 | 16.0 | |
Predorsal fin length 1 | 37.8–41.2 | 39.3 | 37.4–41.3 | 39.2 | 40.3 | 38.1–40.9 | 39.6 | |
Predorsal fin length 2 | 64.9–67.8 | 66.4 | 65.4–69.4 | 67.2 | 65.9 | 63.7–66.7 | 65.2 | |
Preanal fin length | 66.9–71.7 | 69.0 | 64.7–66.3 | 65.4 | 65.3 | 66.0–68.5 | 66.9 | |
Preanal length | 61.0–65.5 | 63.3 | 56.6–60.1 | 58.5 | 58.2 | 60.1–62.0 | 60.9 | |
Prepelvic length | 34.5–39.8 | 37.5 | 36.5–39.1 | 37.5 | 37.2 | 37.5–40.3 | 39.2 | |
Pectoral fin length | 22.5–28.4 | 26.3 | 22.6–27.3 | 25.4 | 26.4 | 24.2–28.5 | 26.6 | |
Prepectoral fin length | 36.9–40.9 | 38.4 | 38.8–42.2 | 40.0 | 38.9 | 38.9–39.6 | 39.3 | |
Pelvic fin length | 16.7–19.8 | 18.5 | 16.3–18.8 | 17.5 | 16.3 | 16.0–19.4 | 17.2 | |
Pelvic fin spine length | 9.5–14.0 | 11.5 | 9.6–11.5 | 10.5 | 10.6 | 10.2–13.0 | 11.5 | |
Lengths of first dorsal fin | ||||||||
1st dorsal-fin spine | 2.4–3.9 | 2.9 | 1.7–4.4 | 2.7 | 2.6 | 2.1–3.0 | 2.6 | |
2nd dorsal-fin spine | 4.4–7.9 | 6.3 | 4.5–8.3 | 6.1 | 6.5 | 5.4–7.4 | 6.4 | |
3rd dorsal-fin spine | 10.0–14.0 | 11.8 | 8.3–12.3 | 10.2 | 11.1 | 10.6–11.3 | 11.0 | |
4th dorsal-fin spine | 14.4–20.6 | 16.5 | 11.6–15.3 | 14.0 | 14.6 | 14.7–14.7 | 14.7 | |
5th dorsal-fin spine | 15.0–20.9 | 17.7 | 12.5–15.8 | 14.1 | 14.8 | 13.7–15.1 | 14.4 | |
Lengths of second dorsal fin | ||||||||
1st dorsal-fin spine | 13.3–17.3 | 15.2 | 10.6–14.1 | 12.2 | 11.1 | 10.4–12.5 | 11.3 | |
1st dorsal-fin ray | 15.4–18.1 | 16.6 | 13.1–15.9 | 15.0 | 15.7 | 14.9–16.7 | 16.0 | |
1st anal-fin spine | 4.0–7.1 | 5.6 | 3.4–5.1 | 4.1 | 5.1 | 5.2–5.7 | 5.5 | |
2nd anal-fin spine | 7.8–14.8 | 11.3 | 8.9–11.2 | 10.1 | 11.9 | 10.6–13.1 | 12.0 | |
3rd anal-fin spine | 8.1–11.1 | 9.3 | 7.9–10.1 | 9.2 | 10.1 | 9.1–11.2 | 10.1 | |
1st anal-fin ray | 12.1–16.9 | 14.2 | 12.2–14.2 | 13.3 | 13.9 | 13.3–15.5 | 14.3 | |
Counts | Mode | Mode | Mode | |||||
Dorsal fin | VIII–IX-I, 8 | IX-I, 8 | X–XI-I, 8–9 | XI-I, 9 | X-I, 8 | IX–X-I, 8 | X-I, 8 | |
Anal fin | III, 5 | III, 5 | III, 5 | III, 5 | III, 5 | III, 5 | III, 5 | |
Pectoral fin | 20–22 | 21 | 19–21 | 20 | 19 | 19–20 | 20 | |
Pored lateral line scales | 34–39 | 36, 37 | 38–41 | 40 | 44 | 40–44 | 43 | |
Gill rakers | 4–5+11–13 | 4+12 | 4–5+14–16 | 5+15 | 5+14 | 4–5+12 | 5+12 |
Mouth large, slightly oblique; maxilla reaching anterior rim of pupil; posterior margin of maxilla with distinct notch. Upper half of maxilla fitting within groove below suborbital ridge. Symphyseal knob absent from lower jaw. Upper and lower jaws with villiform teeth arranged in a band; vomer V-shaped, with villiform teeth; tooth band on palatine narrow.
First dorsal fin originating above level of pectoral-fin base, with usually nine spines (rarely eight), gradually increasing in length to fifth spine. First and second dorsal fins well separated. Second dorsal fin with one spine and eight soft rays; first soft ray somewhat longer than spine. Second dorsal and anal fins opposite each other, nearly equal in length and height; origin of latter slightly posterior to that of former. Caudal fin rounded. Pectoral fin rounded, upper half somewhat longer than lower half; its tip not reaching to level of anus, usually with 20–22 rays (modally 21), the lower 3–8 rays unbranched.
Coloration. In fresh condition, head and body reddish orange, white ventrally; faint dark red saddle below first and second dorsal fins, respectively; fins red, interradial membranes pale red; posterior half of caudal fin dark red. In preserved specimens, head and body pale brown; fins pale gray without any markings.
Known from the western Pacific Ocean; Wakasa Bay of Sea of Japan and Kumano-nada, Pacific coast of Japan and Korea south to China and Taiwan (East China Sea, Yellow Sea, Bohai, and northern part of South China Sea) (Fig.
Distribution of the three species of Parabembras in the Indo-West Pacific. Circles, P. curta; squares, P. robinsoni; stars, P. multisquamata. Closed symbols - based on specimens examined in this study; open symbols - based on literature records. Map was made with layers from Natural Earth, free vector and raster map data at: http://naturalearthdata.com.
Parabembras curta was originally described as a member of Bembras by
The short description of P. curta given by
The record of P. curta from the eastern Indian Ocean by
Parabembras
robinsoni
Regan, 1921: 418, KwaZulu-Natal, South Africa;
Parabembras
curtus
(not of
Parabembras
sp.:
Parabembras robinsoni is distinguished from its congeners in having usually 11 spines in the first dorsal fin (vs. 8–9 in P. curta and 9–10 in P. multisquamata), a distinct symphyseal knob in the lower jaw (vs. symphyseal knob absent in P. curta and P. multisquamata), two preocular spines (vs. single in P. curta and P. multisquamata), and single lachrymal spine (two in P. curta and P. multisquamata).
Measurements are shown in Table
Mouth large, slightly oblique; maxilla reaching level of anterior rim of pupil; posterior margin of maxilla weakly notched. Upper half of maxilla fitting within groove below suborbital ridge. Lower jaw with distinct symphyseal knob. Upper and lower jaws with villiform teeth in a band; vomer V-shaped with villiform teeth; tooth band on palatine narrow.
First dorsal fin originating above level of pectoral-fin base, usually with eleven spines (in some specimens ten), gradually increasing in length to fifth spine. Last spine of first dorsal fin separated from penultimate spine without membrane, positioned midway between penultimate spine of first dorsal fin and insertion of second dorsal fin. Second dorsal fin with one spine and 8–9 soft rays; first soft ray slightly longer than spine. Second dorsal and anal fins directly opposite each other, nearly equal in length and height. Caudal fin rounded. Pectoral fin usually with 19–21 rays (modally 20), lower 4–7 rays unbranched; its rounded upper half somewhat longer than lower half, slightly extending beyond level of anus.
Coloration. In fresh condition, head and body reddish orange, white ventrally; fins red, interradial membranes pale red; distal margins of dorsal and anal fins dark red; posterior half of caudal fin dark red [based on pl. E. Afr-97 of
Western Indian Ocean, from Durban to at least southern Mozambique, along the east coast of South Africa at depths of 200–600 m (
Parabembras robinsoni was originally described by
Parabembras
curtus
(not of
Four specimens.
Parabembras multisquamata is distinguished from P. robinsoni in having two lachrymal spines and no symphyseal knob on the lower jaw. It is most similar to P. curta, but is clearly distinguished from the latter in having usually 10 first dorsal-fin spines (vs. 8 or 9 spines in P. curta), 9–11 supraocular spines (vs. 6–8 in P. curta), and 40–44 pored lateral line scales (vs. 34–39 in P. curta).
Measurements are shown in Table
Mouth large, slightly oblique; maxilla reaching anterior rim of pupil; posterior margin of maxilla with distinct notch. Upper half of maxilla fitting within groove below suborbital ridge. Symphyseal knob absent from lower jaw. Upper and lower jaws with villiform teeth arranged in a band; vomer V-shaped, with villiform teeth; tooth band on palatine narrow.
First dorsal fin originating above level of pectoral-fin base, usually with 10 spines (nine in
Coloration. In fresh specimens [based on fig. 8 in
Known from the western Pacific Ocean, off southwestern Luzon, Philippines, Morobe Province of Papua New Guinea, and Espiritu Santo, Vanuatu. The new species was collected at depths of 299–444 m (Fig.
The name multisquamata is derived from Latin multus meaning many and squamatus meaning scaled, in reference to the high number of pored lateral line scales. The name is an adjective, its ending following the feminine gender of the generic name Parabembras.
1 | Lower jaw with a distinct symphyseal knob; lachrymal with single robust spine [western Indian Ocean] | Parabembras robinsoni |
– | Lower jaw without a symphyseal knob; lachrymal with 2 robust spines | 2 |
2 | First dorsal fin usually with 10 (rarely 9) spines, head with 9–11 supraocular spines, pored lateral line scales 40–44, pectoral fin extending beyond the level of anus [southwestern Pacific Ocean and the Philippines] | Parabembras multisquamata |
– | First dorsal fin with 8 or 9 spines, head with 6–8 supraocular spines, pored lateral line scales 34–39, pectoral fin not reaching to the level of anus [northwestern Pacific Ocean] | Parabembras curta |
Parabembras multisquamata is most similar to P. curta in having two lachrymal spines and no symphyseal knob on the lower jaw, but is clearly distinguished as described above. These two species differ further in some morphometric characters, including the preanal length and the first spine of the second dorsal fin (Fig.
We are grateful to Z. Gabsi and R. Causse (