Scorpaena brevispina Motomura & Senou 2008

Scorpaena brevispina Motomura & Senou 2008 View in CoL

[English name: Japanese Shortspined Scorpionfish; standard Japanese name: Kurenai-fusakasago]

Figs. 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 ; Table 1

Scorpaena brevispina Motomura & Senou 2008: 1762 View in CoL , figs. 1–5 (type locality off Futo, Ito, Shizuoka Prefecture, east coast of Izu Peninsula, Sagami Sea, Pacific coast of Honshu, Japan); Wibowo & Motomura (2021): figs. 2, 5a, 7 (based on holotype).

Holotype: KPM-NI 16667 About KPM-NI (formerly IOP-O-120), 116.1 mm SL, off Ito , Sagami Sea, Honshu, Japan, 34°52′N, 139°08′E, 45 m, A. Ono, 30 June 1982. GoogleMaps

Non-type material examined: Fifteen specimens, 56.0– 114.2 mm SL, all collected from Sagami Sea , Honshu, Japan. KAUM –I. 191886, 82.7 mm SL, KAUM –I. 191887, 73.0 mm SL, off Yokosuka, 75 m, line fishing, A. Kato, 23 Oct. 2023 ; KAUM –I. 192888, 75.5 mm SL, off Yokosuka , 68 m, line fishing, A. Kato, 14 Dec. 2023 ; KAUM –I. 192889, 84.3 mm SL, off Yokosuka , 68 m, line fishing, A. Kato, 4 Dec. 2023 ; KAUM –I. 199426, 86.1 mm SL, off Yokosuka , 68 m, line fishing, A. Kato, 23 Nov. 2023 ; KPM-NI 60407 About KPM-NI , 78.5 mm SL, KPM-NI 60408 About KPM-NI , 74.9 mm SL, off Zushi , 73 m, line fishing, A. Kato, 16 Aug. 2020 ; KPM-NI 60428 About KPM-NI , 74.7 mm SL, off Zushi , 76 m, line fishing, A. Kato & K. Munakata, 21 June 2020 ; KPM-NI 60436 About KPM-NI , 97.7 mm SL, off Zushi , line fishing, A. Kato, 23 Mar. 2021 ; KPM-NI 65196 About KPM-NI , 76.7 mm SL, KPM-NI 65197 About KPM-NI , 71.3 mm SL, off Zushi, line fishing, A. Kato, 26 May 2021 ; KPM-NI 65201 About KPM-NI , 65.9 mm SL, off Zushi , line fishing, A. Kato, 24 May 2021 ; KPM-NI 75505 About KPM-NI , 56.0 mm SL, off Zushi , 70–80 m, line fishing, A. Kato ; KPM-NI 69675 About KPM-NI , 83.3 mm SL, off Hayama , 130 m, line fishing, A. Kato, 9 May. 2024 .

Diagnosis. A species of Scorpaena with the following combination of characters: dorsal-fin soft rays 9; pectoral-fin rays 17; scale rows in longitudinal series 44–46; pored lateral-line scales 23; scale rows above lateral line 5–7 (usually 6), below 11–14 (12 or 13), between sixth dorsal-fin spine base and lateral line 6 or 7, and between last dorsal-fin spine base and lateral line 5–7 (6); pre-dorsal-fin scale rows 3–5 (4); gill rakers 17 or 18 (18); exposed scales covering anteroventral surface of body and base of pectoral fin; anteroventral surface of lower jaw without tentacles; no dermal flap on pectoral-fin axil; anterior surface of preocular spine with three vertical or slightly oblique ridges in large specimens (ca. 100 mm SL); anterior lacrimal spine with 1 or 2 additional spinous points, directed anteroventrally; posterior lacrimal spine simple; lateral lacrimal spine present, with 1 spinous point; anterodorsal lacrimal and coronal spines absent; lateral surface of maxilla without longitudinal ridge; median interorbital ridge absent; occipital pit extremely deep, its length distinctly less than width; body relatively deep (depth 34.9–42.0% of SL); third to fifth dorsal-fin spine lengths 15.9–20.3% of SL, 16.0–20.1% of SL, and 16.1–20.2% of SL, respectively; largest recorded specimen 116.1 mm SL.

Description. Counts and measurements shown in Table 1. Characteristics observed on the majority of additional specimens shown first, with those of the minority in parentheses. Body moderately compressed anteriorly, progressively more compressed posteriorly. Body relatively deep, deepest at pelvic-fin base. Dorsal profile of snout rising gently, forming angle of ca. 45 (35–60) degrees to horizontal axis of head and body. Posterior margin of opercular membrane reaching vertical through fourth dorsal-fin spine base. Short, broad tentacle, with several short branches distally, on posterior edge of low membranous tube associated with anterior nostril. Minute tentacles on outer margin of eye membrane, cheek and lateral body (tentacles absent on cheek). Tentacles on preocular, supraocular, parietal, anterior and posterior lacrimal, first to fifth preopercular, and upper and lower opercular spines (tentacles absent on parietal, first to fifth preopercular, and upper and lower opercular spines); tentacle on supraocular spine large, others minute. Posterior lacrimal spine tentacle linked posteriorly to head by skin. Tentacles absent on anterior margin of lower snout (in anterior view), maxilla, lips, underside of lower jaw, opercle, mid-interorbital space, occiput, and all fin surfaces. Pectoral-fin axil without skin flaps. Embedded ctenoid scales covering posterior half of lateral surface of head, including behind eye, opercle, and area surrounded by parietal, nuchal, pterotic and lower posttemporal spines; embedded cycloid scales covering cheek. No scales on eye membrane, occipital pit, interorbital, snout, maxilla, lower jaw, and each fin membrane and rays. Well-exposed ctenoid scales on lateral surface of trunk. Exposed ctenoid scales covering pectoral-fin base. Embedded cycloid scales covering ventral surface of body between isthmus and posterior to pelvic-fin base. Lateral line sloping steeply downward above anterior half of pectoral fin. Underside of lower jaw with 3 large, well-developed sensory pores on each side, first pore below anterior lacrimal ridge, second below nasal spine, and third on posterior margin of dentary; pores larger than anterior nostril diameter. A pair of small pores behind lower-jaw symphysial knob in ventral view.

Mouth large, slightly oblique, forming angle of ca. 30 (25–35) degrees to horizontal axis of head and body. Posterior margin of maxilla beyond vertical through posterior margin of pupil, not reaching posterior margin of orbit. Upper-jaw with band of short, conical teeth; teeth tips pointed. Tooth band of jaw narrowing posteriorly. Small teeth on vomer and palatines. Underside of lower jaw without ridges.

Origin of first dorsal-fin spine just above lower posttemporal spine tip. Fourth (or third, fifth) dorsal-fin spine longest, fourth (or fifth, sixth) to eleventh spines progressively shorter; membrane of spinous portion moderately incised. All dorsal-fin soft rays branched; third (or second) soft ray longest; posterior margin of soft-rayed portion of dorsal fin rounded; posterior branch of last soft ray strongly joined by membrane to caudal peduncle.Anal fin with 3 spines and 5 soft rays. Origin of first anal-fin spine just below origin of eleventh dorsal-fin spine; first anal-fin spine shortest, second spine longest; all soft rays branched; first (or second) soft ray longest; posterior branch of last soft ray not joined by membrane to caudal peduncle; origin of last soft ray just below origin of sixth dorsal-fin soft ray. Pectoral fin with 1 (or 2) uppermost and 10 (or 9) lowermost rays unbranched, remaining 6 (5 to 7) rays branched; ninth (or tenth) ray longest; lower unbranched rays not thickened; lower pectoral-fin membrane portion slightly incised. Pelvic fin with 1 spine and 5 branched soft rays; second soft ray longest; last soft ray joined by membrane to abdomen for more than half its length. Origin of pelvic-fin spine below midpoint between third and fourth dorsal-fin spine bases. Gill rakers relatively short, spinous; length of longest raker on first gill arch shorter than that of gill filaments around angle of gill arch. No slit behind fourth gill arch.

Nasal spine simple, sharp, conical, directed dorsally, its length slightly greater than posterior nostril diameter. Ascending process of premaxilla not intruding into interorbital space, its posterior margin extending beyond level of anterior margin of posterior nostril in dorsal view, not extending beyond anterior margin of posterior nostril. Median interorbital ridge absent. Interorbital ridges weakly developed, separated by shallow narrow channel, beginning posterior to nasal spines and continuing to tympanic spine base; narrowest distance between ridges directly above anterior margin of pupil. Orbit protruding above head dorsal profile. Preocular spine simple, directed dorsally; tip of spine reaching level with upper margin of pupil in lateral view. Supraocular spine simple, its length slightly less than that of postocular spine. Postocular spine simple, not strongly canted laterally; base wider than tympanic spine base, not joined to interorbital ridge or tympanic spine base. Tympanic spine simple, strongly pointed, directed dorsoposteriorly, with narrow base; base joined to interorbital ridge but not parietal spine base. Coronal spine absent. Occipital pit rectangular in dorsal view, extremely deep with slightly convex center, length distinctly less than width, surrounded laterally by tympanic spines and anterior half of parietal spine bases. A distinct transverse ridge in posterior margin of occipital pit between bases of parietal spines. Parietal spine simple, its base curving strongly into occipital pit. Nuchal spine simple; nuchal and parietal spines joined at base. Sphenotic with 2 (or 3) small spines. Postorbital without spines. Pterotic spine simple, located below parietal and nuchal spines. Two distinct ridges in area surrounded by parietal, nuchal, pterotic and posttemporal spines. Upper posttemporal spine simple, pointed, small, directed dorsoposteriorly, its length same as that of lower posttemporal spine. Lower posttemporal spine simple. Supracleithral spine simple, flattened, not strongly pointed. Cleithral spine flattened, pointed, without a median ridge.

Lateral lacrimal spine absent. Anterior lacrimal spine and single additional spinous point slightly canted anteroventrally, its tip extending beyond dorsal margin of upper lip. Posterior lacrimal spine simple (additional spinous points absent), directed posteroventrally, its tip reaching upper lip, length slightly greater than that of anterior lacrimal spine. Suborbital ridge with three spines, first spine below posterior margin of pupil, second extending beyond orbit, third at end of suborbital ridge. Space between ventral margin of eye and suborbital ridge relatively narrow. Suborbital pit present. Preopercle with five spines; uppermost spine largest, with supplemental preopercular spine on base; second to fifth spines triangular. Preopercle (between uppermost preopercular spine and upper end of preopercle) without serrae or spines. Upper opercular spine simple with a low median ridge. Lower opercular spine simple, with distinct median ridge. Space between upper and lower opercular spines without ridges. Posterior tips of upper and lower opercular spines not reaching opercular margin.

Color of fresh specimens ( Fig. 1A View FIGURE 1 ). Dorsal head and body mainly brilliant red, suffused with irregular blackish and whitish-red. Pectoral-fin base and ventral surface of body pale orange. Dorsal fin mainly bright red, irregularly suffused with blackish and whitish-red, some translucence, entire distal edge white. Anal fin mainly bright red with scattered blackish and whitish-red blotches, base of spines and tips of some soft rays white. Pectoral fin mottled reddish and whitish. Pelvic fin uniformly pale red, margins partly whitish. Caudal-fin rays reddish with scattered white spots, becoming dense on upper (particularly) distal margin; membrane between upper rays colorless, translucent, between lower rays suffused with reddish-orange.

Color of preserved specimens. Head and trunk yellowish-white. Tiny black blotches scattered on lateral surface of head, membranes of spinous portion of dorsal fin, and pectoral-fin membrane. Some specimens with distinct black blotch on membrane between seventh and tenth dorsal-fin spines. No distinct markings on trunk or membranes of soft-rayed portions of all fins.

Biofluorescence emission patterns ( Fig. 2 View FIGURE 2 ). Extremely diverse. Red blotches scattered on postorbital, cheeks, upper eyeball, opercle, pectoral-fin membrane, dorsal-fin membrane, and dorsal body surface in KAUM–I. 191886 ( Fig. 2A View FIGURE 2 ). In KAUM–I. 191887, larger blotch on membrane of spinous portion of dorsal fin between seventh and ninth spines ( Fig. 2B View FIGURE 2 ). Blotches almost absent in KAUM–I. 192888, with a few small blotches scattered on postorbital and dorsal body near the base of soft ray portion of dorsal fin ( Fig. 2C View FIGURE 2 ). KAUM–I. 192889 fully red except for eyeball, snout, lower jaw, ventral body surface, and soft rays of dorsal, anal and caudal fins ( Fig. 2D View FIGURE 2 ).

Distribution. Scorpaena brevispina is currently known only from the Sagami Sea, Honshu, Japan, at depths of 45– 130 m.

Remarks. Scorpaena brevispina was previously known only from a single type specimen and underwater photographs of two individuals ( Motomura & Senou 2008; Wibowo & Motomura 2021). The species is easily distinguished from all other Indo-Pacific congeners, except two Western Australian species ( S. gasta Motomura, Last & Yearsley 2006 and S. sumptuosa Castelnau 1875 ), by having an extremely deep occipital pit, the length distinctly less than width ( Motomura & Senou 2008). Motomura & Senou (2008) also indicated that S. brevispina could be distinguished from S. gasta and S. sumptuosa by the presence of a lateral lacrimal spine, absence of a distinct longitudinal ridge on the lateral surface of the maxilla (vs. distinct ridge present), and 17 pectoral-fin rays (vs. usually 15 in S. gasta , 16 in S. sumptuosa ).

The additional specimens from the Sagami Sea examined in this study were identified as S. brevispina due to their extremely deep occipital pit, of length distinctly less than width, lack of a distinct longitudinal ridge on the lateral surface of the maxilla, and 17 pectoral-fin rays. Although Motomura & Senou (2008) considered that S. brevispina had a lateral lacrimal spine, all 14 non-type specimens examined here were confirmed as lacking that element ( Fig. 3 View FIGURE 3 ). In fact, re-examination of the holotype of S. brevispina revealed a lateral lacrimal spine on the left side only of the specimen, suggesting that S. brevispina usually lacks a lateral lacrimal spine, with the holotype representing an abnormal condition. Although S. brevispina could no longer be distinguished from S. gasta and S. sumptuosa on presence or absence of a lateral lacrimal spine, as believed by Motomura & Senou (2008), the additional specimens examined here revealed that S. brevispina can be distinguished from S. gasta and S. sumptuosa as follows: absence of a distinct longitudinal ridge on the lateral surface of the maxilla (present in the latter); number of pectoral-fin rays (see above); 17 or 18 total gill rakers (vs. 12–15 in S. gasta and S. sumptuosa ); and scale row numbers—longitudinal series 44–46 (vs. 35–42 in S. gasta ), below lateral line 11–14 (vs. 16–18 in S. sumptuosa ), and pre-dorsal 3–5 (vs. 0–2 in S. gasta ) ( Wibowo & Motomura 2021; this study).

On the right side of the holotype, the anterior lacrimal spine was directed anteroventrally, with two additional spinous points of the anterior lacrimal spine directed ventrally. The anterior lacrimal spine in all of the non-type specimens examined here was directed anteroventrally ( Fig. 3 View FIGURE 3 ).

Motomura & Senou (2008) noted three vertical or slightly oblique ridges on the anterior surface of the preocular spine as one of the diagnostic characters of S. brevispina . This study confirmed that most specimens had one or two ridges on the preocular spine surface, but only KPM-NI 63436 had three (indistinct) ridges. In congeners, three such ridges have been reported from a large specimen of S. sumptuosa (see Wibowo &Motomura 2021). Since the holotype of the former [KPM-NI 16667 (116.1 mm SL)] and KPM-NI 63436 (97.7 mm SL) were both larger than the other specimens examined (56.0– 86.1 mm SL), the number of ridges on the preocular spine may increase with growth, as in S. sumptuosa . Although the relationship between ridge number and specimen size needs to be confirmed by examination of further specimens, the character was regarded as diagnostic only for large specimens S. brevispina (> ca. 100 mm SL).

In addition, Wibowo & Motomura (2021) also noted that the pectoral-fin tip extended beyond the first anal-fin spine base in S. brevispina and included this character in their key to Indo-Pacific species of Scorpaena . However, that character is not fixed in the former ( Fig. 1A View FIGURE 1 ), and is not treated here as diagnostic of S. brevispina .

Sexual dichromatism has been reported in 10 species of Scorpaena (see Wibowo & Motomura 2021), males and females of many species being characterized by the presence and absence, respectively, of a blotch on the spinous portion of the dorsal fin. In the 14 specimens examined here, eight had such a black blotch, suggesting that sexual dichromatism in spinous dorsal fin coloring also occurs in S. brevispina .

This study confirmed that S. brevispina has red biofluorescence emission patterns ( Fig. 2 View FIGURE 2 ). Because many marine substrates covered with calcareous algae and corals emit red fluorescence ( Zawada & Mazel 2014), with other studies suggesting that red fluorescence contributes to background matching in benthic fishes, such as scorpionfish ( Anthes et al. 2016; Sparks et al. 2014), it is likely that the red fluorescence of S. brevispina is an adaptation to the benthic environment. In addition, the fluorescence patterns illustrated are extremely diverse ( Fig. 2 View FIGURE 2 ). John et al. (2023) reported that in two species of Scorpaena [ S. maderensis (Valenciennes 1833) and S. porcus (Linnaeus 1758) ], the fluorescent color changes in conjunction with the background color of the individual. The diverse fluorescence emission patterns of S. brevispina observed in this study ( Fig. 2 View FIGURE 2 ) may also be variations that match the background at the time of photography.