Hispidoberyx ambagiosus Kotlyar, 1981

Su, Yo, Lin, Chien-Hsiang & Ho, Hsuan-Ching, 2023, Redescription of the hispidoberycid, Hispidoberyx ambagiosus Kotlyar, 1981 from Taiwan, with comments on its morphology (Beryciformes, Stephanoberycoidei, Hispidoberycidae), ZooKeys 1182, pp. 19-34 : 19

Hispidoberyx ambagiosus Kotlyar, 1981

Figs 1 , 8

Literature records.

Hispidoberyx ambagiosus Kotlyar, 1981: 413 (type locality: off northwestern tip of Sumatra, eastern Indian Ocean, 3°46'00"N, 95°00'00"E, depth 800-875 m. Holotype: ZMMU-P 15416): Yang et al. 1988: 3 (new record from the South China Sea). Kotlyar 1991: 100 (osteology). Kotlyar 1996: 252 (in part). Paxton in Randall and Lim 2000: 600 (listed). Kotlyar 2004: 1 (description). Kimura 2020 (phylogeny).

Specimens examined.

ASIZP 63512, 134.8 mm SL, bottom trawl, depth 650-800 m, 10 Jun. 1999, coll. D.-M. Chen. ASIZP 64539, 154.7 mm SL, bottom trawl, 28 Aug. 2002, coll. H.-C. Ho. ASIZP 76178, 153.5 mm SL, bottom trawl, 24 Apr. 2015, coll. M.-Y. Lee. ASIZP 81665, 162.0 mm SL, bottom trawl, 25 July 2020, coll. C.-H. Lin et al. All collected from Daxi fishing port (ca 24°53'37"N, 121°55'26"E), Yilan, northeastern Taiwan .

Otolith (a pair of sagittae): CHLOL 969, otolith length 2.2 (left) and 2.3 (right) mm, taken from ASIZP 81665.

Description of Taiwanese specimens.

Meristic and morphometric data are provided in Tables 1 and 2 .

Dorsal-fin elements V, 10-11, first 2 spines fused in 2 specimens (Fig. 3A ). Pectoral-fin elements 12/12-13, uppermost 2 and lowermost 1 or 2 rays unbranched. Pelvic-fin elements I, 7/I, 7. Anal fin-elements II-III, 10, first 2 spines fused in all specimens (Fig. 4B ; 1 specimen unavailable). Principal caudal-fin rays 10 + 9, uppermost and lowermost rays unbranched; procurrent caudal-fin rays 9-10 on both upper and lower lobes. Gill rakers on outer face of first arch 4-5 + 1 + 10-13 = 15-19 (total). Pseudobranchial filaments 10-11. Lateral-line scales 33-36/33-36; scale rows above lateral line 15-18; scale rows below lateral line 27-31. Vertebrae 13 + 23 = 36; branchiostegal rays 8.

Body slender for stephanoberycoid, greatest depth 3.4-3.9 in SL, depth at dorsal- and anal-fin origins 3.6-4.5 and 4.5-5.5 in SL, respectively; body laterally compressed and oval in trunk section, its width 4.4-4.7 in SL. Head somewhat oval, length 3.2-3.3 in SL; its height 1.4-1.5 in HL; upper profile of head nearly straight, gently curved to dorsal-fin origin; forehead flat, HF1 14.3-20.3 and HF2 5.3-5.9 in HL; eye diameter 4.8-5.8 in HL; tip of snout slightly rounded, not extending before premaxilla, its length 3.3-3.5 in HL; interorbital width 2.8-2.9 in HL.

Mouth oblique, upper-jaw length 1.5 in HL; posterior end of maxilla rounded, reaching vertical through posterior margin of eye; lower jaw slightly larger than upper jaw and protruding before upper jaw, length 1.3-1.5 in HL. Two nostrils at same horizontal through center of eye; both nostrils rounded, slightly oval, with posterior nostril much larger than anterior one; both nostrils immediately in front of eye. Tominaga’s organ (Fig. 4 ; sensu Paxton et al. 2001) present in olfactory chamber, mostly embedded behind nasal organ (Fig. 4 ). Nasal organ large and oval, bearing leaf-like appendages.

Symphysis of premaxillae notched and edentate. Symphysis of dentaries slightly notched and edentate. Supramaxilla single, with long needle-like process extending anteriorly and rectangular process posteriorly; covering about half of posterior portion of maxilla.

Bony ridges associated with skeletons of head, jaws, snout, and operculum covered with small spinules. Bony ridges on head forming sensory canals (Fig. 5 ); supraorbital canal running from nasal, frontal, connected to coronal commissure at parietal bones, and divided into temporal and supratemporal canal on posttemporal bone, and joined together, connected to lateral line. Fenestration present on frontal bone connecting coronal commissure and temporal canal (Fig. 5 ; red arrow). Opercle with 1 strong central spine. Posttemporal bone without spine. Pectoral girdle smooth, without any spines. Premaxilla with villiform teeth, its outer surface completely exposed and bearing 2 or 3 ridges anteriorly on its ascending process; its end extending to posterior end of maxilla. Dentary with villiform teeth on its medial face. Palatine and vomer with villiform teeth.

Gill rakers rod-shaped, laterally compressed, their inner surfaces covered with small teeth; rakers on outer row of first arch longer than remainder, longest gill raker shorter than eye diameter; small bump-like rakers on inner surfaces of outer 3 arches; outer-row rakers gradually shorter from first to fourth arch, with very short rakers on outer row of fourth arch; no tooth patches present between rakers on all 4 arches. Narrow, villiform tooth patch present on fifth ceratobranchial. Long, oval tooth patch on third epibranchial arch. Large, teardrop-like villiform tooth patch on third pharyngobranchial. Small, rounded villiform tooth patch on fourth pharyngobranchial. Gill filaments on first arch short, about 1/3-1/2 length of longest opposite rakers. Pseudobranch present and short.

Prickle-like body scales adherent (Fig. 6A ), covering entire body, operculum, and cheeks; spinules on body scales needle-like and curved backwards, their numbers variable: scales on nape with ca 2-7 spinules; scales on abdominal region with 2-7 spinules; scales on dorsum with 2-14 spinules; scales above anal-fin base with 4-11 spinules; scales on caudal peduncle with 3-16 spinules. Lateral-line scales shield shaped (Fig. 6B, C ) with 2 posterior branches, each bearing 1-3 (modally 2) spines curving backwards; center of each scale with 2 or 3 (rarely 1) central spines curving and pointing backwards; all lateral-line scales distinctly larger than body scales; lateral-line canals opened at both anterior and posterior ends of scales. No scutes on abdominal region. No scales on gular region and isthmus. Predorsal scales not enlarged and not aligned in straight line.

Dorsal fin low, situated posteriorly, slightly anterior to anal-fin origin. Origin of pectoral fin situated lower than horizontal through ventral margin of eye. Origin of pelvic fin below and slightly behind pectoral-fin base. Both pectoral and pelvic fins short, their tips clearly anterior to vertical through anal-fin origin. Anal-fin base rather short, its end at same vertical through end of dorsal-fin base. Caudal fin moderately small, slightly forked. All fin rays fragile and possess spinules on lateral surfaces, except for procurrent caudal-fin rays (sometimes also absent on anterior most dorsal- and anal-fin spines).

Lateral line single, originating behind and slightly lower than posterior tip of posttemporal bone; its anterior portion slightly curved and raised, with downturn below dorsal-fin base, and nearly straight posterior portion; its end anterior to caudal-fin base. Anus situated immediately anterior to anal-fin origin. Caudal peduncle stout, length 1.3 in HL, height 3.7-4.1 in HL. Light organs absent. No trace of swim bladder.

Otoliths.

(Fig. 7 ). Otoltihs triangular, with horizontal, long ventral rim, oblique posterior and anterior rims, and short but rounded dorsal rim. Slightly notched in anterior rim, forming brief but obtuse rostrum and antirostrum. All margins smooth. Otoliths notably thickened, with inner and outer faces nearly flat. Sulcus centrally positioned, not divided into ostium and cauda, open anteriorly, slightly bent upward posteriorly but not reaching posterior rim. Cristae not well delineated. Single, large colliculum centrally located, but shape of its posterior margin varies greatly; largely extended posteriorly in right otolith, but deeply indented in left one.

Coloration.

When fresh (Fig. 1 ), entire body, including head, fin rays, and fin membranes uniformly pinkish to reddish. When preserved (Fig. 2 ), body uniformly pale, including entire oral cavity, gill rakers, inner face of operculum, stomach, and intestine. Membrane of kidney and ventral side of peritoneum scattered with pepper-like black pigments. Pelvic fin slightly dusky, while other fins pale.

Size.

This is a moderately small species of stephanoberycoid, attaining at least 181 mm SL (holotype; Kotlyar 1981). Our largest specimen (ASIZP 81665; 162.0 mm SL) is a mature female with developing eggs, suggesting that it may mature at this size.

Figures

Figure 1. Fresh specimens of Hispidoberyx ambagiosus Kotlyar, 1981 A ASIZP 64539, 154.7 mm SL (after a few months of refrigeration) B ASIZP 81665, 162.0 mm SL. Photographed by J. - F. Huang. Not to scale.

Figure 2. Preserved specimens of Hispidoberyx ambagiosus Kotlyar, 1981. A ASIZP 63512, 134.8 mm SL B ASIZP 64539, 154.7 mm SL C ASIZP 76178, 153.5 mm SL D ASIZP 81665, 162.0 mm SL. Not to scale.

Figure 3. Close-up images of Hispidoberyx ambagiosus Kotlyar, 1981, ASIZP 63512, 134.8 mm SL, featuring the fusion of the first two spines on (A) dorsal and (B) and anal fins (tips indicated by arrows). Scale bar: 500 μm.

Figure 4. Close-up image of Hispidoberyx ambagiosus Kotlyar, 1981, ASIZP 63512, 134.8 mm SL, featuring the nasal organ (white arrow) in the right olfactory chamber. Red arrow indicates the position of Tominaga's organ (beneath and behind nasal organ). Anterior to right. Scale bar: 1 mm.

Figure 5. Dorsal-lateral view of Hispidoberyx ambagiosus Kotlyar, 1981, ASIZP 81665, 162.0 mm SL, showing sensory canals (white) on head and nearby bones (black). Red arrow indicates the fenestration connecting COR and TC. Abbreviations: COR, coronal commissure; Fr, frontal; LL, lateral line; Na, nasal; Pa, parietal; Pt, posttemporal; SOC, supraorbital canal; STC, supratemporal canal; TC, temporal canal. Anterior to left. Not to scale.

Figure 6. Body and lateral-line scales of Hispidoberyx ambagiosus Kotlyar, 1981, ASIZP 81665, 162.0 mm SL. A body scales on nape B lateral-line scales on anterior portion C lateral-line scales on posterior portion. Anterior to left. Scale bars: 500 μm.

Figure 7. Otoliths (a pair of sagittae) of Hispidoberyx ambagiosus Kotlyar, 1981. Specimens (CHLOL 969) were taken from ASIZP 81665 A, B left otolith, 2.2 mm otolith length C, D right otolith, 2.3 mm otolith length A, C ventral views B, D inner (mesial) views. Scale bar: 1 mm.

Figure 8. Distribution map of Hispidoberyx ambagiosus Kotlyar, 1981. Data source: star = this study; triangle = Kotlyar (1981); square = Yang et al. (1988); circle = Kotlyar (1991).