Cirrhilabrus rubrisquamis Randall & Emery, 1983

Tea, Yi-Kai, Najeeb, Ahmed, Rowlett, Joseph & Rocha, Luiz A., 2022, Cirrhilabrus finifenmaa (Teleostei, Labridae), a new species of fairy wrasse from the Maldives, with comments on the taxonomic identity of C. rubrisquamis and C. wakanda, ZooKeys 1088, pp. 65-80 : 65

Cirrhilabrus rubrisquamis Randall & Emery, 1983

Rosy-scaled Fairy Wrasse Fig. 1

Cirrhilabrus rubrisquamis Randall & Emery, 1983: 21; fig. 1 (description); Winterbottom et al. 1989: 53; pl VII-E (checklist, fishes of the Chagos Archipelago); Winterbottom and Anderson 1997: 15 (revised checklist, fishes of the Chagos Archipelago)

Holotype.

Cirrhilabrus rubrisquamis : ROM 35932, 40.6 mm SL, juvenile, Isla Fouquet, Peros Banhos Atoll, Chagos Archipelago (5°21'3"S, 71°48'57"E).

Diagnosis.

Cirrhilabrus rubrisquamis shares similar meristic characters to other members of this genus, in particular C. wakanda (the potential synonymy of both species is discussed below). However, the holotype is readily distinguished from related congeners in having the following combination of characters: lateral line with 21 or 22 pored scales (15 or 16 in the dorso-anterior series, six in the posterior peduncular series); gill rakers 16; caudal fin round with blue and yellow vermiculation in life; dorsal two-thirds of body with purple scales arranged in a chain-link pattern in life.

Description.

Dorsal-fin rays XI,9; all soft rays branched except first; anal-fin rays III,9; all soft rays branched except first; last dorsal and anal-fin ray branched to base; pectoral-fin rays 15/15, upper two unbranched; pelvic-fin rays I,5; principal caudal-fin rays 7+6, uppermost and lowermost unbranched; upper procurrent caudal-fin rays 5, lower procurrent caudal-fin rays 5; lateral line interrupted, with dorso-anterior series of pored scales 16/15 and midlateral posterior peduncular series 6/6; first pored scale on posterior peduncular series often pitted; last pored scale on posterior peduncular series enlarged and overlapping hypural crease; scales above lateral line to origin of dorsal fin 2; scales below lateral line to origin of anal fin 6; median predorsal scales 5; median prepelvic scales 5; rows of scales on cheek 2; circumpeduncular scales 16; gill rakers 5 + 11 = 16; pseudobranchial filament count not made, owing to small size of specimen; vertebrae 9 + 16; epineurals 12.

Body moderately elongate and compressed, depth 3.5 in SL, width 2.2 in depth; head length (HL) 2.9 in SL; snout pointed, its length 3.6 in HL; orbit diameter 3.5 in HL; depth of caudal peduncle 2.1 in HL. Mouth small, terminal, and oblique, with maxilla almost reaching vertical at front edge of orbit; dentition typical of genus with three pairs of canine teeth present anteriorly at side of upper jaw, first forward-projecting, next two strongly recurved and outcurved, third longest; an irregular row of very small conical teeth medial to upper canines; lower jaw with a single stout pair of canines anteriorly which protrude obliquely outward and are slightly lateral to medial pair of upper jaw; no teeth on roof of mouth.

Posterior margin of preopercle with 29/27 very fine serrations; margins of posterior and ventral edges of preopercle free to about level of middle pupil. Anterior nostril in short membranous tube, located nearer to orbit than snout tip; posterior nostril larger, roughly ovoid to rectangular, located just medial and anterior to upper edge of eye. Scales cycloid; head scaled except snout and interorbital space; six large scales on opercle; a broad naked zone on membranous edge of preopercle; a row of large, elongate, pointed scales along base of dorsal fin, one per element, scales progressively shorter posteriorly on soft portion of fin; anal fin with a similar basal row of scales; last pored scale of lateral line (posterior to hypural plate) enlarged and pointed; one scale above and below last pored scale also enlarged; pectoral fins naked except for a few small scales at extreme base; a single large scale at base of each pelvic fin, about three-fourths length of pelvic spine.

Origin of dorsal fin above second or third lateral-line scale, predorsal length 2.7 in SL; first 1-5 dorsal-fin spines progressively longer, sixth to tenth subequal, eleventh longest, 2.3 in HL; interspinous membranes of dorsal fin in males extend beyond dorsal-fin spines, with each membrane extending in a pointed cirri beyond spine; eighth dorsal-fin soft ray longest, 2.0 in HL, remaining rays progressively shorter; origin of anal fin below base of tenth dorsal-fin spine; third anal-fin spine longest, 2.4 in HL; interspinous membranes of anal fin extended as on dorsal fin; anal-fin soft rays relatively uniform in length, eighth longest, 1.9 in HL; dorsal and anal-fin rays just reaching caudal-fin base; caudal fin rounded; pectoral fins short, reaching vertical between bases of fourth or fifth dorsal-fin spines, longest ray 1.8 in HL; origin of pelvic fins below lower base of pectoral fins; pelvic fins short, not reaching past anal fin origin, longest ray 1.8 in HL.

Coloration of holotype in life.

Based on color photograph of holotype when fresh (Fig. 1 ): head yellow, brownish posteriorly; lower part of head whitish to pale pink; preopercle prominently purple on outer edge; iris yellow; body orangey pink, fading to whitish pink ventrally; body with a network of dark purple scales arranged in a chain link pattern from just after dorsal fin origin to edge of caudal peduncle, absent from lower third of body; dorsal fin hyaline, yellow on distal half; posterior dorsal fin yellowish hyaline with metallic blue spots; caudal fin bluish hyaline with yellow and blue vermiculation, often broken in spots; anal fin similar to dorsal fin; pelvic fins hyaline; pectoral fin base with a purple band; pectoral fins pinkish hyaline.

Coloration of holotype in alcohol.

Uniformly pale tan, median and paired fins translucent hyaline. No evidence of purple scale markings, likely due to immaturity and/or loss of coloration over time.

Figures

Figure 1. Cirrhilabrus rubrisquamis, ROM 35932, 40.6 mm SL, juvenile holotype, Isla Fouquet, Peros Banhos Atoll, Chagos Archipelago. Photograph by AR Emery and R Winterbottom.