Terelabrus toretore Shepherd, Pinheiro, Phelps

Shepherd, Bart, Pinheiro, Hudson T., Phelps, Tyler A. Y., Siu, Gilles & Rocha, Luiz A., 2023, sp. nov. (Perciformes: Labridae), a New Species of Striped Hogfish from Tahiti, with Range Extensions for Two Congeners., Zoological Studies 62 (8), pp. 1-13 : 3-8

Terelabrus toretore Shepherd, Pinheiro, Phelps ,

Siu and Rocha sp. nov. Common name: Tahitian striped hogfish

( Figs. 1 , 2 , 3 ; Table 2)

urn:lsid:zoobank.org:act:62B6B7A8-D061-41C6-A08B-73B5EB77D13A

Type locality: Tahiti, French Polynesia.

Holotype: CAS-ICH 247318, field code: HTP927, GenBank OP 721249. 58.3 mm SL, Tahiti , French Polynesia, - 17.528673°S, - 149.579084°W, depth of collection 140 m, collected with hand nets by HT Pinheiro, TAY Phelps, MV Bell, B Shepherd, and LA Rocha, 5 March 2019.

Paratype: CAS-ICH 247319, field code: HTP928, GenBank OP721250. 44.3 mm SL, same data as holotype.

Etymology: The species name, toretore, is the Tahitian word for striped and is used in reference to the body color pattern. To be used as a noun in apposition.

Diagnosis: Terelabrus toretore sp. nov. can be distinguished from the other four members of the genus by the following characters: 43–44 scaled rows in longitudinal series; 42 pored lateral-line scales; 5 + 10 gill rakers; 10 scale rows below lateral line; a relatively long snout (snout length 9.6–9.7% SL); 8 posterior branches on the main supratemporal sensory canal, and a coloration consisting of a yellow caudal fin, and a wide, red, mid-lateral stripe with no blotching, the space above which is white anteriorly, becoming yellow from beneath the dorsal fin to the caudal peduncle.

Description: Dorsal fin X, 11; anal fin III, 12; pectoral fin with 15 soft rays, all branched except first and second; pelvic fin I, 5; principal caudal rays 14; branched caudal rays 12; upper procurrent caudal rays 9, the most posterior segmented; lower procurrent caudal rays 8 (9), the most posterior segmented; scale rows in longitudinal series 43 (44); pored lateral-line scales 42; scale rows above lateral line to origin of dorsal fin 3; scale rows below lateral line to origin of anal fin 10; scale rows on cheek 5; gill rakers 5 + 10; formula for configuration of supraneural bones, anterior neural spines and anterior dorsal pterygiophores //0/1 + 1/1/1/1/1/1/1/1/1; vertebrae 11 + 17.

Body depth 13.9 (15.6); body width 9.3 (8.8); head length 33.8 (32.3); snout length 9.6 (9.7); orbit diameter 8.1 (7.7); interorbital width 4.6 (4.3); upperjaw length 7.9 (8.1); postorbital length 14.1 (13.5); caudal-peduncle length 15.3 (17.6); caudal-peduncle depth 8.2 (8.6); pre-dorsal-fin length 32.8 (35.2); preanal-fin length 57.1 (57.3); pre-pelvic-fin length 32.6 (33.0); dorsal-fin base length 48.9 (50.1); first dorsal-fin spine length 4.8 (5.0); second dorsal-fin spine length 6.7 (5.9); third dorsal-fin spine length 7.9 (8.6); tenth dorsal-fin spine length 8.7 (9.5); longest dorsal-fin soft ray the eighth (seventh), its length 10.8 (12.2); anal-fin base length 29.2 (30.2); first anal-fin spine length 3.3 (2.7); second anal-fin spine length 6.5 (5.2); third anal-fin spine length 7.4 (6.8); longest anal-fin soft ray the fifth (sixth), its length 9.8 (9.3); pectoral-fin length 14.4 (15.3); pelvic-fin length 13.2 (11.5); least distance between anteroventral margin of orbit and maxilla 1.7 (1.6).

Body elongate, cylindrical, becoming more compressed posteriorly. Snout long and pointed. Eye very large, interorbital space slightly convex. Mouth terminal, gape oblique; posterior margin of maxilla does not extend to a vertical through the anterior margin of orbit; inner surface of upper lip with 5 oblique fleshy ridges with small dense papillae; inner surface of lower lip with two fleshy ridges without papillae; lower lip with thin flap extending ventrally on side of jaw. Teeth in jaws affixed to outer edge of bony ridge; two pairs of large, slender, strongly-curved canine teeth anteriorly in each jaw, followed by ten smaller, slender canine teeth along each side of upper jaw, the two posteriormost slightly larger; a forward-projecting canine posteriorly on upper jaw (at corner of mouth); each of the pair of upper pharyngeal bones triangular with numerous, small, nodular teeth; row of ten conical teeth along each side of lower jaw, followed by row of seven small teeth. Tongue slender, its upper surface covered with small papillae. Gill rakers short, compressed; rakers on upper limb shorter than those on lower limb; longest raker on first gill arch about half length of longest gill filament; gill membranes free from isthmus.

Nasal organ in oval chamber with convex cutaneous roof; anterior nostril small with short membranous tube. Supratemporal canal with eight pored branches, four per side on both types. Scales thin, cycloid; lateral-line scales continuous, following dorsal contour of body; posterior scales descending toward lateral midline; last two pored scales on base of caudal fin larger than more anterior pored scales; each pored scale on anterior lateral line upwardly angled with a single terminal pore, upwards angle decreases progressively from below end of soft dorsal fin towards completely horizontal tubule at base of caudal fin. Lateral line scales notched at pore, with notches larger posteriorly. Scales become progressively smaller anteriorly. Scales in front of dorsal fin extending forward to vertical through preopercular margin, predorsal scales variable in size. Scales covering opercle, except for membrane. Largest scale behind orbit much smaller than those on opercle; scales of suborbital region smaller, extending forward to below anterior edge of pupil; rest of head naked. No scales on fins, except at base of caudal fin.

Preopercular margin smooth. Opercular membrane extending above upper base of pectoral fin. All dorsal-, anal-, and pelvic-fin soft rays branched; all pectoral-fin rays, except upper two, branched. Dorsal- and anal-fin spines slender. Pectoral fins weakly rounded, seventh ray the longest; pelvic fins short, second ray the longest; caudal fin rounded. Origin of dorsal fin slightly posterior to vertical through origin of pectoral fin; posterior tip of pectoral fin aligns with vertical between base of sixth and seventh dorsal-fin spines; origin of pelvic fin aligns with vertical through origin of lower base of pectoral fin; anus located beneath vertical between eighth and ninth dorsal-fin spine bases; origin of anal fin below base of ninth dorsal-fin spine.

Coloration: body white with two wide longitudinal red stripes extending from tip of snout to caudal peduncle; the greatest width of the mid-lateral red stripe about the same as diameter of orbit. Mid-lateral red stripe continuous, solid, and without bars or blotches. Upper red stripe extends from snout, above eye, to caudal peduncle, its width diminishing posteriorly. The space between the two red stripes begins just anterior to the orbit as a thin white line, which continues through the iris, extending the length of the body and becoming wider and more yellow posteriorly. At the caudal peduncle, this yellow region is approximately the same width as the mid-lateral red stripe. Dorsal surface of snout and head predominantly red; white under jaw, below orbit, on throat, lower half of operculum, and on belly from origin of pelvic fins to base of caudal peduncle. Pronounced dark blotch superimposed on mid-lateral red stripe on opercle, approximately the same diameter as pupil; dark blotch retains pigmentation through preservation. Less pronounced dark blotch on mid-lateral red stripe immediately posterior to eye. Pupil black; red and white longitudinal stripes on body continue through iris in life; iris red in fresh (dead) specimens. Pectoral fins hyaline, with faint red fin rays; pelvic fins white; dorsal fin hyaline with faint red and yellow coloration on spines and rays; caudal fin predominantly yellow with faint red markings on dorsal and ventral margins; anal fin hyaline with white and yellow coloration on spines and rays. Color in preservation: pale straw, except for spot of pigmentation on posterior operculum and faint spotting along midlateral red stripe.

Distribution and habitat: Terelabrus toretore sp. nov. is currently only known from Tahiti and Moorea, but is likely to be widely distributed in French Polynesia. Terelabrus toretore sp. nov. was found at depths around 120–140 m on rubble substrates of deep slopes and steep walls. The wall where the specimens were collected was a sheer vertical slope, even negative in some places, and presented narrow vertical caves and holes with an invertebrate fauna dominated by encrusting sponges, gorgonians and black corals. Several (always solitary) individuals of Terelabrus toretore sp. nov. were observed, swimming quickly a few centimeters above the reef.

Coloration of T. zonalis : Here we also present the first description of coloration of a fresh specimen of T. zonalis ( Fig. 4 ). Body overall light pink dorsally, silvery-white ventrally. A series of regularly-spaced vertical bars, light pink in color and numbering approximately 25 in the photographed specimen, spans the length of the body from behind the pectoral fins to the caudal peduncle. These light pink bars are interspersed with the silvery-white body coloration. Head pink above orbit, silvery-white ventrally, with pronounced yellow stripe extending from upper lip through eye to operculum; three parallel yellow stripes behind eye, one aligned with the upper margin of eye, another with center, and the third with lower margin; middle and lower stripes continue on preopercle and operculum; upper one dorsally on head. Pupil black; iris red with yellow margin. Lower jaw, throat and belly silvery-white. Pectoral fins hyaline; caudal fin pink with bright yellow stripes on dorsal and ventral margins; dorsal, pelvic and anal fins not visible in photo, coloration unknown. Single dark spot, slightly smaller than pupil and irregularly shaped, at upper margin of operculum just anterior to pectoral fin base.

Molecular Phylogenetics: Our analysis shows that the five presently described species Terelabrus cluster into a well-supported monophyletic group ( Fig. 5 ). The Australasian T. zonalis and the Indian Ocean T. flavocephalus are closely related and well-separated from the three western and central Pacific species. The most widely distributed species ( T. rubrovitattus ) is sister to the pair formed by the western Pacific T. dewapyle and the south Pacific T. toretore .

Figures

Fig. 1. Coloration of freshly dead specimens of Terelabrus toretore sp. nov. (A) holotype CAS-ICH 247318 (SL 58.3 mm), and (B) paratype CAS- ICH 247319 (SL 44.3 mm).

Fig. 2. Preserved coloration and radiograph of the holotype CAS-ICH 247318 (SL 58.3 mm). Photograph and radiograph by Jon Fong.

Fig. 3. Underwater photographs of Terelabrus toretore (specimens not collected): (A) Tahiti at 125 m depth, photo by L.A. Rocha; (B) Moorea at 252 m depth, photo by R. Holler (Tahiti Private Expeditions).

Fig. 4. Queensland Museum specimen number QM I.41018 from the Great Barrier Reef Myrmidon Reef), Australia, identified as Terelabrus zonalis (SL 64.3 mm). Photograph by James Foster. This is the only known photograph showing the fresh coloration of this species.

Fig. 5. Bayesian phylogenetic analysis of the genus Terelabrus based on mitochondrial DNA cytochrome oxidase subunit I (COI). Node support values next to the branches correspond to the posterior probabilities of the Bayesian analysis. Scale bar is the number of nucleotide substitutions per site.