Pterois russelii Bennett, 1831

Matsunuma, Mizuki, Bogorodsky, Sergey V., Motomura, Hiroyuki & Mal, Ahmad O., 2016, Objective record of Pterois russelii (Scorpaenidae: Pteroinae) from the Red Sea, Cybium 40 (4), pp. 333-337 : 334-336

Pterois russelii Bennett, 1831

( Fig. 1 )

Pterois russelii Bennett, 1831: 128 (Coromandel coast, India, eastern Indian Ocean; no types preserved): Frøiland, 1972: 80 (Eilat, Israel, Red Sea); Dor, 1984: 86 (Red Sea; listed); Goren and Dor, 1994: 21 (Red Sea; listed).

Material examined

SMF 35752 ( KAU 14-168 ) , 99.7 mm SL, off Jizan, Saudi Arabia, Red Sea (16°58.569’N, 42°20.764’E), over soft substrata, 30-32 m, S . V. Bogorodsky et al., bottom trawl, 1 Nov. 2014 .

Description

Dorsal-fin rays XII, 11 (abnormal condition; usually XIII, 11 in the species; see Remarks); anal-fin rays III, 7; pectoral-fin rays 13 (both sides); pelvic-fin rays I, 5. Pored lateral-line scales 28; scale rows in longitudinal series 72; scales above lateral line 10; scales below lateral line 14; scale rows between last dorsal-fin spine base and lateral line 9; scale rows between sixth dorsal-fin spine base and lateral line 8; predorsal-fin scale rows 4; oblique cheek scale row 6; horizontal cheek scale row 3; vertical cheek scale row 4. Gill rakers 5 + 11 (2 rakers on hypobranchial). Branchiostegal rays 6. The following morphometrics are expressed as percentage of SL: body depth at pelvic-fin origin 33.2; body depth at anal-fin origin 28.1; body width 20.9; head length 38.1; head width 11.0; head depth 15.1; snout length 13.7; interorbital width at mid-orbit level 9.0; interorbital width at preocular spine base 7.6; upper-jaw length 6.3; maxillary depth 6.0; postorbital length 18.5; suborbital depth 4.7; predorsal-fin length 32.3; preanal-fin length 69.2; prepelvic-fin length 37.8; caudal-peduncle length 19.1; caudal-peduncle depth 11.2; first dorsal-fin spine length (DS) 19.2; second DS 28.9; third DS broken; fourth DS 36.8; fifth DS 36.2; sixth DS 38.2; seventh DS 38.2; eighth DS 36.7; ninth DS 34.7; tenth DS 26.2; eleventh DS 16.4; twelfth DS 15.3; first dorsal-fin soft ray length 21.0; longest dorsal-fin soft ray length 36.5 (fourth); first anal-fin spine length ( AS) 7.8; second AS 13.7; third AS 17.0; first anal-fin soft ray length 32.2; longest anal-fin soft ray length 38.4 (third); first pectoral-fin ray length 103.1; pelvic-fin spine length 19.1; longest pelvic-fin soft ray length 51.9 (second); caudal-fin length 48.6.

Body oblong, moderately compressed; depth moderate, slightly less than longest dorsal-fin spine length. Caudal peduncle relatively short, low, its depth less than its length. Head large, its length greater than body depth. A pair of short barbels on tip of snout, the length of barbel subequal to anterior nostril flap. A short, pointed flap with a median expansion on posterior edge of low membranous tube associated with anterior nostril. Supraocular with a moderately long tentacle with wavy lateral ridges, its length 1.2 times orbit diameter. Two small elongate, leaf-like flaps on preopercle margin below third preopercular spine base; upper and lower flaps on tips of fourth and fifth preopercular spine, respectively. An extremely small skin flap anterodorsally on orbit surface; its length shorter than anterior nostril diameter. Two elongate, leaf-like flaps on ventral margin of lacrimal; anterior and posterior flaps on tips of anterior and posterior lacrimal spine, respectively; posterior flap relatively long (its length 1.5 times anterior flap length), its tip extending beyond posterior margin of maxilla when laid back. Head and body covered with small cycloid scales (ctenoid scales absent); snout, both jaws, mandible, lacrimal, interopercular and occipital area without scales. Suprapostorbital region bordered by pterotic, posttemporal and parietal-nuchal spine base generally naked but with few small scattered cycloid scales.

Mouth moderately large, slightly oblique, forming an angle of ca. 30° to horizontal axis of head. Anterior region of maxilla with a poorly developed median lateral ridge; upper edge of posterior maxilla swollen laterally, forming a low ridge; posterior margin of maxilla broadly rounded, just reaching level with anterior margin of pupil. Symphyseal gap separating premaxillary teeth bands broader than width of each band; both jaws with a narrow band of small, slender conical teeth; about 6-8 and 7 tooth rows at widest portion of upper and lower teeth bands, respectively; small conical teeth forming blunt V-shaped patch on vomer, about 6 tooth rows at widest portion; palatine teeth absent. Underside of dentary with three sensory pores on each side, middle pore presented by complex of three minute pores; two small pores on each side of symphysial knob of lower jaw on each side. Gill rakers on first gill arch short, tips slightly expanded.

Dorsal profile of snout moderately steep, forming an angle of ca. 40° to horizontal axis of head. Nasal spine single. Preocular spine with a spinous point directed dorsally. Supraocular spine with a spinous point covered by base of supraocular tentacle. Postocular spine large with a spinous point directed laterally (absent on right side). Interorbital ridge poorly developed, diverging anteriorly and posteriorly in dorsal view; interorbital canal narrow, shallow. Coronal and tympanic spines absent. Parietal with a single ridge with a spinous point on posterior end. Nuchal with a single ridge completely fused to parietal ridge, with a single spinous point on posterior end. Occipital area shallow, undeveloped. Postorbital spine absent. Sphenotic region with one (two on right side) small spine. Pterotic, lower posttemporal and cleithrum with a short ridge with a small spine. Lateral lacrimal ridge short, without spine. Suborbital ridge divided into anterior and posterior portions, end of each portion with a spinous point. Anterior lacrimal spine with a single spinous point, directed ventrally. Posterior lacrimal portion platelike with a spinous point distally. Preopercle with four (five) spines, upper three (two) spines prominent, lower two spines reduced and skin-covered; no supplemental spine. Opercular spine absent.

Dorsal-, anal- and pelvic-fin spines with deep grooves (most likely associated with venom glands). Origin of first dorsal-fin spine above pterotic spine base; bases of first and second dorsal-fin spines closer than those of subsequent adjacent spines; sixth or seventh spine longest; interspinous membranes of dorsal fin deeply incised. All but first dorsal-fin ray branched; fourth ray longest, its length distinctly less than that of longest dorsal-fin spine; posteriormost ray free from caudal peduncle. Origin of first anal-fin spine below last (twelfth) dorsal-fin spine base; third spine longest. Anal-fin soft rays all branched; third ray longest, its length slightly longer than that of longest dorsal-fin soft ray; posteriormost ray free from caudal peduncle. Pectoral fin extremely long, its length greater than SL, its tip far beyond level of caudal-fin base; membranes incised, but reaching along rays to tips; lower four rays slightly thickened. Pelvic-fin spine base below second dorsal-fin spine base; all soft rays branched; second soft ray longest, its tip reaching level of fifth anal-fin soft ray base when laid along body; posteriormost soft ray with membranous connection to abdomen for approximately one-fifth of ray length. Caudal fin moderately long, its length 1.3 times head length, with rounded contour; three (dorsal series damaged) procurrent rays, two (dorsal series damaged) segmented unbranched rays, and five segmented branched rays in dorsal and ventral series.

Colour of fresh specimen (based on figure 1). – Ground colour of head and body whitish with pale red tinge, more whitish ventrally. Snout side with two narrow brown bands, anterior band running along bulge on snout, posterior band from preocular, extending onto anterior lacrimal flap. Three bars below eye: anteriormost bar narrow, orange, reaching from anteroventral margin of orbit to posterior lacrimal flap base; middle bar relatively broad, somewhat orange-brown, reaching from supraocular tentacle base, across orbit ventrally, to posteroventral margin of preopercle; posteriormost bar narrow, pale orange, reaching from posteroventral margin of orbit to posterior margin of preopercle. Four orange to brown bands saddling nape, extending onto opercle: anteriormost band brown, curved, relatively broad at level of occipital region; second band paler, at level of origin of parietal-nuchal spine base; third band brown, broad at level of central portion of parietal-nuchal ridge; posteriormost band paler, narrower below parietal-nuchal spine base. Supraocular tentacle and orbit surface flap black; other skin flaps on head same as head ground colour. Eye vivid yellow (iris tinged with red by blood); pupil dark blue. Twelve or more (uncertainty due to damage posteriorly on body) transverse brown bars on body side, alternating broad and narrow. Body bars extending basally onto dorsal and anal fins. Thorax without band markings. A few small, poorly defined, white spots scattered along lateral line. A large, irregular, rounded blotch (slightly larger than pupil) behind dorsoposterior margin of the opercle. Dorsal-fin ray coloration similar to ground colour of body, membrane more reddish; soft-rayed portion without any distinct marking but a minute black spot on membrane between first and second rays. Anal-fin coloration similar to that of dorsal fin but dusky distally, with a few small white rounded blotches basally; three minute black spots scattered on soft-rayed portion. Pectoral-fin coloration similar to that of ground colour of body, membrane of upper and posterior portion of fin strongly blackish, with about seven poorly defined bands. Pelvic-fin spine white, soft rays and membrane black, with numerous small white rounded to oval spots (smaller than iris). Caudal-fin coloration faded due to specimen condition, without spots.

Remarks

The examined specimen agreed with descriptions and figures of P. russelii given in previous studies ( Smith, 1957; Poss, 1999; Matsunuma, 2011, 2013) in having III, 7 anal-fin rays; 13 pectoral-fin rays; 72 scale rows in longitudinal series; coronal and tympanic spines absent; the head and body not covered with ctenoid scales; the soft-rayed portion of the dorsal and anal fins and caudal fin without numerous spots, being distinct rows; and the pelvic fin with numerous white spots. Although the specimen unusually possessed 12 dorsal-fin spines, 13 being normal for the species, the former is regarded as an abnormal condition with no further significance. The specimen, relatively small in size of 99.7 mm SL, possessed well developed supraocular tentacles, of length 120% of orbit diameter, whereas large specimens recorded in previous studies (e.g., Smith, 1957: 24.5 cm total length specimen from South Africa; Randall, 1995: 34 cm specimen from Oman) possesses either reduced supraocular tentacles or none at all. Examination of the Red Sea and other examined specimens of P. russelii indicated that the supraocular tentacles become reduced and shorter with growth in the species ( Fig. 2 ). The Red Sea specimen was collected by trawl off Jizan from depths of 30-32 m over soft substrata far from coral reefs and islands, typical habitat of P. russelii , which is rarely seen close to coral reefs.

Only three species of Pterois were listed by Goren and Dor (1994) in their checklist of Red Sea fishes: P. miles , P. radiata Cuvier in Cuvier & Valenciennes, 1829, and P. russelii . Later, Matsunuma and Motomura (2015) concluded that P. radiata in the Red Sea was in fact the closely related species Pterois cincta Rüppell, 1838 , the latter having long been included in the synonymy of the former. Although Debelius (1998) reproduced an underwater photograph of Pterois mombasae ( Smith, 1957) from Jordan, that was subject to a locality error (D. Golani, pers. com.). Among the congeners occurring in the Red Sea, P. russelii most resembles P. miles in general body appearance, both species sharing a large body (exceeding 20 cm), the orbit highly set on the head (and broadly separated from the suborbital ridge) and the upper pectoral-fin rays neither filamentous nor free from membranes. However, P. russelii can be distinguished from P. miles in having more dorsal-fin [10-12 (strongly modally 11) versus 9-11 (10) in the latter] and anal-fin soft rays [6-8 (7) versus 6 (rarely 5)], and slightly fewer pectoral-fin rays [12-14 (13) versus 13 or 14 (14)] ( Schultz, 1986; this study). Moreover, P. russelii differs from P. miles by having slightly fewer scale rows in the longitudinal series (69-91 versus 79-96 in the latter) and scale rows below the lateral line (13-20 versus 17-23), but those counts also overlapped. Coloration is the most useful feature for separating the two species, P. russelii possessing a plain caudal fin and the soft-rayed portion of the dorsal and anal fins without spots (rarely a few spots present), whereas those fins had numerous rounded dark spots, forming distinct rows in P. miles ( Poss, 1999; this study). Pterois cincta , also endemic to the Red Sea, is readily distinguishable from P. russelii by having 15 or more pectoral-fin rays (versus 12-14 in the latter), 51-57 scale rows in the longitudinal series (versus 69-91), the orbit close to the suborbital ridge (versus well separated) and the upper pectoral-fin rays with short associated membrane and filamentous (versus not filamentous or free from membrane) ( Smith, 1957; Matsunuma and Motomura, 2014, 2015; this study).

The record of P. russelii from the Red Sea (Eilat, Israel) in Frøiland (1972) was supported by a drawing of that species. However, the latter was reproduced from Smith (1957: fig. 6) and not based on the examined specimen (TAU NS 1114, 146.0 mm SL), which was characterized as follows: XIII, 11 (as XIII + 11 1/2) dorsal-fin rays; 13 pectoral-fin rays; III, 7 (as III + 7 1/2) anal-fin rays; and 88 scale rows in the longitudinal series under “Material examined”. However, the “Description” included: dorsal-fin rays XIII, 11 (10-12); anal-fin rays III, 7(8); pectoral-fin rays 13 (12-14); and scale rows in the longitudinal series 70-88, clearly indicating either a number of specimens examined or published data included, as opposed to a single specimen. Notwithstanding, the number of fin rays given specifically for the Eilat specimen agreed with those of P. russelii rather than P. miles . Moreover, Frøiland (1972) described that specimen as possessing a few spots on the caudal-fin and soft-rayed portions of the dorsal and anal fins, features consistent with P. russelii . Accordingly, Frøiland’s (1972) specimen can be identified as having been P. russelii . Although a second specimen (TAU 4006) from Eilat had previously also been identified as P. russelii , it is now recognized as P. cincta , having XII, 10 dorsal-fin rays, III, 6 anal-fin rays and 17 pectoral-fin rays. Therefore, the specimen described herein represents the sole currently available example of P. russelii from the Red Sea. Occasional records of P. russelii in the Red Sea might be explained by its typical habitat in open areas with silty sand bottom rarely visited by divers, in contrast to P. cincta and P. miles usually inhabiting coral reefs ( Allen and Erdmann, 2012; Matsunuma and Motomura, 2015).

Acknowledgments. – We are deeply grateful to M. McGrouther, A. Hay, and S. Reader (AMS); K.-T. Shao, Y.-C. Liao, and M.-Y. Lee (ASIZP); J. Maclaine and O. Crimmen (BMNH); H. Endo, T. Yamakawa, N. Nakayama (BSKU); T. Nakabo, Y. Kai (FAKU), T. Nakabo and N. Muto (formerly FAKU); K. Swagel (FMNH); M.Yabe, H. Imamura, and T. Kawai (HUMZ); H. Senou (KPM); P. Pruvost, R. Causse, Z. Gabsi, C. Ferrara, and P. Béarez (MNHN); M.-D. Wandhammer (MZS); Z. Arifin, R. Pratiwi, M. Adrim, I. Alhakim, and K. Wibowo (NCIP); H.-C. Ho (NMMB); M. Gomon and D. Bray (NMV); A. Palandacic (NMW); K. Matsuura and G. Shinohara (NSMT); I.-S. Chen (NTOU); K.-Y. Wu (NTUM); K. Hatooka (OMNH); U. Satapoomin (PMBC); R. de Ruiter (RMNH); R. Bills and O. Gon (SAIAB); H. Zetzsche (SMF); T. Yoshino (formerly URM); J. Williams (USNM); P. Bartsch and C. Lamour (ZMB); and K. Sakamoto (ZUMT) for their kind hospitality during the first author’s visits to their institutions. We are indebted to D. Catania (CAS), A. Suzumoto (BPBM), T. Noichi (CMNH), and R. Feeney (LACM) for providing opportunities to examine specimens. The scientific research cooperation between King Abdulaziz University (KAU), Faculty of Marine Sciences (FMS), Jeddah, Saudi Arabia, and the Senckenberg Research Institute (SRI), Frankfurt, Germany, in the framework of the Red Sea Biodiversity Project, during which the present material was collected, was funded by KAU GRANT NO. “D/1/432-DSR”. The authors acknowledge, with thanks, KAU and SRI for technical and financial support as well as A.Al-Aidaroos (KAU), F. Krupp (SRI and Qatar Natural History Museum, Doha), and T.J. Alpermann (SRI) for his comprehensive assistance. We especially thank M. Goren (Tel Aviv University) for providing information on the Frøiland specimen; students and volunteers of KAUM for curatorial assistance and sampling of specimens; and G. Hardy (Ngunguru, New Zealand) for reading the manuscript and providing help with English. This study was supported in part by Grants-in-Aid for Scientific Research (A: 26241027, B: 24370041 and C: 23580259 and 26450265) from the Japan Society for the Promotion of Science, Tokyo, Japan (JSPS); the JSPS Asian Core Program, “Establishment of Research and Education Network on Coastal Marine Science in Southeast Asia”; the “Coastal Area Capability Enhancement in Southeast Asia Project” of the Research Institute for Humanity and Nature, Kyoto, Japan; and the “Biological Properties of Biodiversity Hotspots in Japan ” project of the National Museum of Nature and Science, Tsukuba, Japan.

Figures

Figure 1. – Fresh specimen of Pterois rus- selii from the Red Sea [SMF 35752 (KAU 14-168), 99.7 mm standard length, off Jizan, Saudi Arabia]. Photo by S. V. Bogorodsky.

Figure 2. – Relationship between supraocular tentacle length and standard length (mm) in Pterois russelii, showing ontogenetic change of the former.