Terelabrus toretore sp. nov. (Perciformes: Labridae), a New Species of Striped Hogfish from Tahiti, with Range Extensions for Two Congeners

© 2023 Academia Sinica, Taiwan Open Access Terelabrus toretore sp. nov. (Perciformes: Labridae), a New Species of Striped Hogfish from Tahiti, with Range Extensions for Two Congeners Bart Shepherd1,*, Hudson T. Pinheiro2,3 , Tyler A.Y. Phelps2, Gilles Siu4, and Luiz A. Rocha2 1Steinhart Aquarium, California Academy of Sciences, San Francisco, CA 94118, USA. *Correspondence: [email protected] (Shepherd) 2Department of Ichthyology, California Academy of Sciences, San Francisco, CA 94118, USA. E-mail: [email protected] (Pinheiro); [email protected] (Phelps); [email protected] (Rocha) 3Center for Marine Biology, University of São Paulo, São Sebastião, SP 11612-109, Brazil 4PSL Research University, EPHE-UPVD-CNRS, USR 3278 CRIOBE, Laboratoire d’Excellence “Corail”, BP 1013, 98729 Papetoai, Moorea, French Polynesia. E-mail: [email protected] (Siu) Received 3 August 2022 / Accepted 14 December 2022 / Published 31 March 2023 Communicated by Felipe Ottoni A new labrid fish, Terelabrus toretore sp. nov., the fifth species within the genus, is herein described from two specimens collected at a depth of 140 m from a mesophotic coral ecosystem in Tahiti, French Polynesia. Terelabrus toretore sp. nov. is characterized by having 43–44 scaled rows in longitudinal series; 42 pored lateral-line scales; 5+10 gill rakers; 10 scale rows below the lateral line; 8 posterior branches on the main supratemporal sensory canal; a relatively long snout (snout length 9.6–9.7% SL), 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 predominantly yellow from beneath the dorsal fin to the caudal peduncle. In addition to describing this new species, we document the first record of Terelabrus rubrovittatus from the Republic of Marshall Islands, and the first record of Terelabrus zonalis from Australia, along with the first description of its coloration. We present a molecular phylogeny of the genus based upon mitochondrial cytochrome c oxidase subunit I (COI) DNA sequences. Key words: Biogeography, Ichthyology, Mesophotic coral ecosystems, Taxonomy, Teleostei. Citation: Shepherd B, Pinheiro HT, Phelps TAY, Siu G, Rocha LA. 2023. Terelabrus toretore sp. nov. (Perciformes: Labridae), a new species of striped hogfish from Tahiti, with range extensions for two congeners. Zool Stud 62:08. doi:10.6620/ZS.2023.62-08. BACKGROUND There are currently four described species of striped hogfish within the genus Terelabrus Randall and Fourmanoir 1998, all of which were collected from mesophotic reefs (50–150 m depth; Rocha et al. 2018) in locations across the Pacific and Indian Oceans. Terelabrus rubrovittatus Randall and Fourmanoir 1998, the first member of the genus to be described, initially was known only from a single specimen caught in a trap at a depth of 100 m in New Caledonia. A second specimen was collected at a depth of 92 m in Papua New Guinea (Randall and Fourmanoir, 1998). Nearly 20 years later, the second species in the genus, Terelabrus dewapyle Fukui and Motomura 2015 was described from five specimens collected in southern Japan, Papua New Guinea, and Fiji. Again, the specimens were collected from mesophotic coral ecosystems at depths of 72–92 m. The following year, a third species was described from the Maldives: Terelabrus flavocephalus Fukui and Motomura 2016 was first seen in an underwater photograph and later described from a single specimen acquired from the marine aquarium trade. The most recently described species, Terelabrus zonalis Fukui 2018, is known only from two preserved specimens collected by trawl at a Zoological Studies 62: 8 (2023) doi:10.6620/ZS.2023.62-08 1 © 2023 Academia Sinica, Taiwan depth of 73–84 m in the Philippines. Terelabrus are small, fast swimming labrid fishes, characterized by an elongated, cylindrical body, large eyes and a body coloration typically consisting of alternating longitudinal stripes of red and yellow or white, which extend along the full length of the body. Important characters used to differentiate between the species include the number of scale rows in longitudinal series, the number of gill rakers, the number of posterior branches of the main supratemporal sensory canal, and color (Fukui 2018). As with numerous other new fishes that have been recently described from deep reefs, these species have been described using only a single or small number of specimens but are likely common in their habitat (Sih et al. 2017; Coleman et al. 2018; Pinheiro et al. 2019). While conducting ichthyological surveys on mesophotic ecosystems in French Polynesia in early 2019, we collected two specimens of a presumed new species of Terelabrus. Later that year, we collected two specimens of another species of Terelabrus during a research expedition to the Marshall Islands. The latter species, upon closer examination of their coloration and morphology, was identified as T. rubrovittatus. Furthermore, in July 2020, Tahiti Private Expeditions, while testing an ROV on the northern coast of Moorea at depths to 300 m, took pictures of a previously unknown species of Terelabrus. Here we describe the species from French Polynesia as Terelabrus toretore sp. nov., and report T. rubrovittatus for the Marshall Islands for the first time, representing a large range extension for the species. We also document the first record of T. zonalis outside of the Philippines, a specimen collected on the Great Barrier Reef and held in the Queensland Museum, and describe its coloration for the first time. Finally, we present a phylogeny of the genus based upon mitochondrial DNA. MATERIALS AND METHODS All specimens were collected with hand nets while diving on mixed-gas closed-circuit rebreather (Hollis Prism 2) in French Polynesia (Tahiti, Moorea) and Micronesia (Majuro, Republic of Marshall Islands). Specimens were collected and immediately transported to a field laboratory, where they were photographed, tissues sampled, fixed in 10% formalin, and preserved in 75% ethanol. The preserved specimens were later measured and x-rayed at the California Academy of Sciences. Measurements were taken with digital calipers to the nearest 0.01 mm and rounded to one decimal place, following the conventions described in Fukui (2018) and Fukui and Motomura (2015 2016). All measurements were taken on the left side of the body with the aid of a dissecting microscope. Principal and procurrent caudal-fin ray counts are presented as upper + lower. Vertebral counts are presented as precaudal + caudal. The anterior-most vertebra with a haemal spine was counted as the first caudal vertebra, and the urostylar complex was counted as the last. Gill raker counts are presented as upper (epibranchial) + lower (ceratobranchial) rakers on the anterior face of the first arch; the angle raker is included in the second count. The anterior supraneural-dorsal ray-pterygiophore-neural spine interdigitation pattern is presented as a formula with “0” representing a supraneural, “/” a neural spine, and numerals indicating the number of spines borne by each pterygiophore (Anderson and Heemstra 2012; Williams et al. 2013). Measurements in the text are proportions of standard length (SL), unless otherwise noted. Values in parentheses are for the paratype, when different from the holotype. The holotype and paratype were deposited into the California Academy of Sciences ichthyological collection (CAS). Mitochondrial cytochrome c oxidase subunit I (COI) DNA was sequenced and analyzed for the new species. DNA extraction and PCR amplification of the COI gene were performed following protocols detailed in Weigt et al. (2012). DNA sequences of other Terelabrus species and three outgroups were obtained from Genbank and the Barcode of Life Database, and aligned to new sequences obtained by our team for Terelabrus flavocephalus from the Maldives, T. dewapyle from the Philippines, and T. rubrovittatus from the Marshall Islands. Specimen voucher numbers and sequence accession numbers are given in table 1. Alignments of DNA sequences were done using a standard Geneious global alignment with free end gaps and 65% similarity in the program Geneious Prime 2022.2.2 (Biomatters, Auckland; Kearse et al. 2012). In the most complete Labridae molecular phylogeny published to date, Aiello et al. (2017) show that Terelabrus is a member of the tribe Hypsigenyini (hogfishes and tuskfishes) with no clear close relative. Therefore we chose three members of that tribe (Achoerodus viridis Steindachner 1866; Bodianus trilineatus Fowler 1934; and Lachnolaimus maximus Walbaum 1792) as outgroups for our phylogeny. Analyses used a Bayesian approach performed with MrBayes 3.2.7 (Ronquist et al. 2012), with two runs and four chains (one cold, three heated) per run implemented in Geneious Prime. The Metropoliscoupled Markov Monte Carlo chains were run for 10 million generations, sampled every 1,000 generations, and the first 2,500 samples were discarded as burn-in (25%). The evolutionary model implemented by Mr. Bayes is GTR + I + G, and the outputs of the analyses page 2 of 13Zoological Studies 62: 8 (2023) © 2023 Academia Sinica, Taiwan were visualized with Geneous Prime. Topologies of three independent runs were identical. RESULTS 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-A08B73B5EB77D13A Type locality: Tahiti, French Polynesia. Holotype: CAS-ICH 247318, field code: HTP927, GenBank OP721249. 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 dorsalfin 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); analfin 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 Table 1. Sequence accession numbers (GenBank for all species, except T. zonalis, which is only accessioned in the Barcode of Life database) and specimen voucher numbers for sequences used in the phylogenetic analysis Species Sequence accession # Specimen voucher # Lachnolaimus maximus JQ841241 BZLWD7678 Bodianus trilineatus JF492970 ADC220.9-1 Achoerodus viridis EF609278 BIOUG:BW-A1227 Terelabrus dewapyle OP721251 CAS-ICH 243200 Terelabrus flavocephalus OP721248 CAS-ICH 247321 Terelabrus rubrovittatus OP721247 CAS-ICH 247320 Terelabrus toretore OP721249 CAS-ICH 247318 Terelabrus toretore OP721250 CAS-ICH 247319 Terelabrus zonalis FOAQ440-21 QM I.41018 page 3 of 13Zoological Studies 62: 8 (2023) © 2023 Academia Sinica, Taiwan 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. Dorsaland anal-fin spines slender. Pectoral fins weakly rounded, seventh ray the longest; pelvic fins short, second ray the longest; Fig. 1. Coloration of freshly dead specimens of Terelabrus toretore sp. nov. (A) holotype CAS-ICH 247318 (SL 58.3 mm), and (B) paratype CASICH 247319 (SL 44.3 mm). page 4 of 13Zoological Studies 62: 8 (2023) © 2023 Academia Sinica, Taiwan 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 midlateral 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 Fig. 2. Preserved coloration and radiograph of the holotype CAS-ICH 247318 (SL 58.3 mm). Photograph and radiograph by Jon Fong. page 5 of 13Zoological Studies 62: 8 (2023) © 2023 Academia Sinica, Taiwan 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 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). A B page 6 of 13Zoological Studies 62: 8 (2023) © 2023 Academia Sinica, Taiwan 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 Table 2. Meristic counts and morphometric measurements of Terelabrus toretore sp. nov., and two specimens of Terelabrus rubrovittatus, a new record for Majuro (Republic of Marshall Islands) Terelabrus toretore sp. nov. Terelabrus rubrovittatus HOLOTYPE PARATYPE CAS-ICH 247318 CAS-ICH 247319 CAS-ICH 247320 Standard length (mm) 58.3 44.3 71.3 41.2 Dorsal-fin rays X, 11 X, 11 X, 11 X, 11 Pectoral-fin rays 15 15 15 15 Pelvic-fin rays I, 5 I, 5 I, 5 I, 5 Anal-fin rays III, 12 III, 12 III, 12 III, 12 Caudal-fin rays (branched) 14 (12) 14 (12) 14 (12) 14 (12) Scale rows in longitudinal series 43 44 46 46 Pored lateral-line scales 42 42 43 43 Scale rows above lateral line 3 3 3 3 Scale rows below lateral line 10 10 12 12 Scale rows on cheek 5 5 5 4 Scale rows between orbit and preopercular margin 4 4 6 5 Pre-dorsal-fin scale rows 8 8 7 7 Gill rakers 5+10 5+10 4+9 5+9 Vertebrae 11+17 11+17 11+17 11+17 Body depth 13.9 15.6 14.4 15.5 Body width 9.3 8.8 9.0 8.3 Head length 33.8 32.3 29.2 31.3 Snout length 9.6 9.7 8.3 7.5 Orbit diameter 8.1 7.7 8.3 8.5 Interorbital width 4.6 4.3 6.9 5.8 Upper-jaw length 7.9 8.1 9.0 7.3 Postorbital length 14.1 13.5 15.4 13.6 Caudal-peduncle length 15.3 17.6 14.0 12.4 Caudal-peduncle depth 8.2 8.6 9.0 9.7 Pre-dorsal-fin length 32.8 35.2 30.7 35.0 Pre-anal-fin length 57.1 57.3 57.6 56.8 Pre-pelvic-fin length 32.6 33.0 32.4 31.6 Dorsal-fin base length 48.9 50.1 54.3 49.5 1st dorsal-fin spine length 4.8 5.0 5.5 5.1 2nd dorsal fin spine length 6.7 5.9 7.3 6.6 3rd dorsal-fin spine length 7.9 8.6 8.1 7.3 10th dorsal-fin spine length 8.7 9.5 9.5 7.8 Longest dorsal-fin soft ray length (number) 10.8 (8th) 12.2 (7th) 13.3 (8th) 9.0 (7th) Anal-fin base length 29.2 30.2 28.6 28.6 1st anal-fin spine length 3.3 2.7 3.2 3.2 2nd anal-fin spine length 6.5 5.2 4.3 5.3 3rd anal-fin spine length 7.4 6.8 6.6 6.3 Longest anal-fin soft ray length (number) 9.8 (5th) 9.3 (6th) 10.0 (5th) 10.0 (5th) Pectoral-fin length 14.4 15.3 15.7 16.7 Pelvic-fin length 13.2 11.5 13.6 11.9 Least distance between anteroventral margin of orbit and maxilla 1.7 1.6 1.8 1.9 page 7 of 13Zoological Studies 62: 8 (2023) © 2023 Academia Sinica, Taiwan 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. DISCUSSION Fukui’s (2018) key to the species of Terelabrus employs the following characters as important diagnostics for the genus: number of scale rows in longitudinal series; number of pored lateral-line scales; number of gill rakers; the anatomy of the main supratemporal sensory canal, particularly the number of posterior branches; the number of dorsal and ventral caudal-procurrent rays; and coloration of fresh specimens. Accordingly, Terelabrus toretore sp. nov. differs from all its congeners by the total number of supratemporal pored branches (8 versus 4, 5, 6, 9 or 10) and snout length (greater than 9.5% of SL versus 6.4– 8.5% of SL) (Table 3). The new species most resembles T. zonalis in the number of scale rows in longitudinal series (43–44), the number of lateral line scales (42), and scale rows below the lateral line (10). It can be distinguished from T. zonalis by the total number of gill rakers (15 in T. toretore, versus 11–12 in T. zonalis), by having a more slender body (body width 8.8–9.3% SL in T. toretore, versus 11.4–12.8% SL in T. zonalis), by having a longer snout (snout length 9.6–9.7% SL in T. toretore, versus 6.4–6.8% SL in T. zonalis), and by having a longer caudal peduncle (caudal peduncle length 15.3–17.6% SL in T. toretore, versus 12.2–12.6% SL in T. zonalis). Terelabrus toretore sp. nov. resembles T. rubrovittatus in the number of gill rakers (14–15), but can be distinguished from it by the lower number of scale rows in longitudinal series (43–44 in T. toretore, versus 45–48 in T. rubrovittatus), the number of lateral line scales (42 in T. toretore, versus 43–45 in T. rubrovittatus), the number of scale rows below the lateral line (10 in T. toretore, versus 11–12 in T. rubrovittatus), by having a longer snout (snout length 9.6–9.7% SL in T. toretore, versus 5.9–8.5% SL in T. rubrovittatus), by a smaller interorbital width (4.3–4.6% SL in T. toretore, versus 5.3–6.6% SL in T. rubrovittatus), by its longer third dorsal-fin spine length (7.9–8.6% SL in T. toretore, versus 5.4–7.1% 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. page 8 of 13Zoological Studies 62: 8 (2023) © 2023 Academia Sinica, Taiwan SL in T. rubrovittatus), longer third anal-fin spine length (6.8–7.4% SL in T. toretore, versus 5.0–5.9% SL in T. rubrovittatus), by the number of posterior branches on the main supratemporal sensory canal (8 in T. toretore, versus 4–5 in T. rubrovittatus), and by coloration. Terelabrus toretore sp. nov. has a yellow dorsal line between the two mid-lateral red stripes and a completely yellow caudal fin, compared to a white dorsal line between the two mid-lateral red stripes and the red mid-lateral line extending into the white caudal fin characterizing T. rubrovittatus. In coloration, Terelabrus toretore sp. nov. most resembles T. dewapyle and T. flavocephalus. It can be distinguished by the number of scale rows in longitudinal series (43–44 in T. toretore, versus 41–42 in T. dewapyle and 46 in T. flavocephalus), the number of pored lateral-line scales (42 in T. toretore, versus 39–40 in T. dewapyle and 44 in T. flavocephalus), by the number of gill rakers (5+10 = 15 in T. toretore, versus 4–5 + 8–9 = 12–13 in T. dewapyle, and 4+9 = 13 in T. flavocephalus). In addition, it can be distinguished from T. dewapyle by the number of scale rows between the orbit and the preopercular margin (4 in T. toretore, versus 5–6 in T. dewapyle), by the number of scale rows below the lateral line (10 in T. toretore, versus 11–12 in T. dewapyle), by the number of posterior branches on the main supratemporal sensory canal (8 in T. toretore versus 4–6 in T. dewapyle), and in coloration: having 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. Table 3. Comparison of selected characters among the species of Terelabrus Species Scale rows in longitudinal series Pored lateral-line scales Gill rakers Scale rows below lateral line Snout length (% SL) Posterior branches on main supratemporal sensory canal Terelabrus toretore sp. nov. 43–44 42 15 10 9.6 (9.7) 8 Terelabrus rubrovittatus (Randall and Fourmanoir 1998) 45–48 43–45 14–15 11–12 8.0 (5.9–8.5) 4–5 Terelabrus dewapyle (Fukui and Motomura 2015) 41–42 39–40 12–13 11–12 8.5 (6.6–7.9) 4–6 Terelabrus flavocephalus (Fukui and Motomura 2016) 46 44 13 10 7.8 9 Terelabrus zonalis (Fukui 2018) 44 42 11–12 10 6.4 (6.8) 10 page 9 of 13Zoological Studies 62: 8 (2023)