Parapercis rota, new species

Figures 1B, 2, 3; table 1

HOLOTYPE: AMNH 277100, 44.3 mm SL; Western Province, Solomon Islands, Peava Island; ROV-based rotenone collection from anchor just offshore and outside of Peava Island lagoon; 187 m depth; 8°47’03.3”S 158°14’08.7”E; JSS-SI19-010; J.S. Sparks, N. Chaloux, and B. T. Phillips, July 28, 2019.

DIAGNOSIS: The new species is readily distinguished from all congeners by a unique pigmentation pattern, comprising four large, rounded, orangish-olive saddles dorsally on the flank, each with a large distinct dorsomedial white spot completely enclosed within the saddles, such that they resemble wheels, plus a much smaller fifth saddle on the caudal peduncle with only a small white dorsomedial spot, 10 discrete broad, dark orangish-olive oval vertical bars below the lateral midline, a single row of dark spots on the soft dorsal fin, the caudal fin is lined dorsally and ventrally with stripes of yellowish-olive pigmentation extending the length of the fin, and two prominent dark brown to black spots at the caudal-fin base.

DESCRIPTION: Selected proportional measurements and meristic data presented in table 1. Body elongate and moderately dorsoventrally depressed anteriorly. Body becoming rounded and tubular in cross section medially, and increasingly laterally compressed posteriorly. Head dorsoventrally depressed, particularly anteriorly, and not elongate. Snout short, weakly pointed in lateral profile. Snout more or less rounded in dorsal view. Predorsal profile mostly straight. Orbits very large. Eyes dorsolaterally oriented and fully visible (= included) in dorsal view. Interorbital width roughly half of orbit diameter. Suborbital distance slightly less than orbit height. Nape broad and flattened. Mouth relatively wide and moderate in size, slightly oblique, and jaws not elongate. Posterior margin of maxilla extending to a vertical approximately at anterior margin of orbit. Upper lip generally broad throughout. Lower lip broader anteromedially, becoming progressively narrow posteriorly. Lower jaw weakly prognathous. Rostral margin of lower jaw protruding slightly anterior to upper jaw. Symphysis of lower jaw rounded in shape in ventral view. Fleshy flap present below lower jaw.

Interorbital series comprised of seven elements, including lacrimal, with posterior, uppermost element firmly attached to neurocranium. Posterior margin of preopercle appears smooth, but with very fine serrations that are barely visible even under magnification. Opercle bearing a single well-developed spine. Midcaudal margin of subopercle bears three prominent serrations that resemble teeth. Operculum extending just anterior of a vertical at origin of spinous dorsal fin. Gill membranes free of isthmus, but with broad and substantial, medial flap of tissue.

Upper jaw with outer row of large, slightly recurved caniniform teeth, and an anteromedial band comprising several rows (four rows anteromedially) of much smaller villiform to small conical teeth. Villiform and small conical teeth in upper jaw restricted medially. Greatly enlarged outer canine teeth in upper jaw number three to four on each side, with the second or third tooth from symphysis of upper jaw largest. Posterolateral to greatly enlarged teeth surrounding symphysis, caniniform outer row teeth becoming progressively smaller posteriorly. Outermost row on lower jaw comprised of three large, recurved canine teeth on each side, with posteriormost, third tooth in series largest. A broad anteromedial band of small villiform to conical teeth present in lower jaw with multiple rows medially (three rows anteromedially), tapering to a single row posteriorly. Posterior teeth becoming caniniform and somewhat larger than those anterior in lower jaw. Vomer with two to three (medially) rows of very stout, slightly recurved conical teeth. Palatine teeth absent.

Lower limb of first gill arch with 10 elongate and triangular rakers, comprising nine denticulate outer ceratobranchial rakers, and one smaller hypobranchial raker of same morphology. Other rakers on arches two to four considerably shorter and more robust. These rakers highly denticulate apically with denticles directed medially. Six branchiostegals present.

Scales on flank and opercle comparatively large and strongly ctenoid. Smaller ctenoid scales present on caudal fin, and extending approximately 1/2 to 2/3 length of fin. Scales on nape reduced in size. Scales on nape cycloid anteriorly and becoming weakly ctenoid posteriorly. Scales on cheek numerous and cycloid, much smaller than those on flank. Ventrum fully scaled. Interpelvic chest scales and scales below pectoral insertion markedly reduced in size, cycloid anteriorly and becoming increasingly ctenoid posteriorly. Lacrimal, snout, and occiput asquamate. Nine or 10 scales in diagonal from dorsal margin of opercle to origin of spinous dorsal fin. Seven scales in diagonal from lateral line to first ray of soft dorsal fin. Nine predorsal scales along dorsal midline. Pored scales in lateral line 58.

Fin spine and soft-ray counts as follows: dorsal V, 21; anal I, 17; pectoral 17; pelvic I, 5; principal caudal rays 9 upper + 7 lower, all branched. Vertebral count 10 precaudal + 19 caudal = 29. Anteriormost three to four vertebral centra noticeably reduced in size when viewed laterally. Dorsal insertion of pectoral fin at about level of vertical through origin of spinous dorsal fin; pectoral fin extending posteriorly to vertical through eighth soft dorsal-fin ray when adducted. Pelvic-fin origin at about level of vertical through posterior margin of opercle and extending to just past third anal-fin ray when adducted. Membrane of fifth dorsal spine attached to first ray of soft dorsal at about 1/2 of length of fifth spine measured from fin base. Anal-fin origin at vertical through fifth ray of soft dorsal fin. Soft dorsal terminating slightly anterior to anal-fin termination. Caudal fin relatively short and weakly emarginate.

PIGMENTATION IN LIFE: Coloration of the freshly collected holotype is shown in figure 2. Pigmentation pattern on the upper flank comprises four large orangish-olive saddles, each with a distinct dorsomedial white spot comprising multiple scales that is completely surrounded by a wide margin of darker pigmentation, plus a fifth saddle on the caudal peduncle with only a very small dorsomedial white dot. Each saddle is broadly outlined in white. Scales within the flank saddles are outlined in dark olive. Saddles with burgundy pigmentation dorsally, neon green medially, and with dark red stripes along their ventral margin. There are 10 discrete, dark orangish-olive oval vertical bars below the lateral midline, and two prominent dark brown to black spots at the caudal fin base, with the lower spot somewhat smaller and more diffuse than the upper. The chest and belly are white and somewhat iridescent. The dorsal fin is hyaline with a single row of well-defined dark olive spots at about 2/3 length of the dorsal spines and rays spanning the length of the soft dorsal fin, and also with some dark olive pigmentation distally. The caudal fin is hyaline centrally and distally along the posterior margin, somewhat white centrally, and with stripes of yellowish-olive pigmentation dorsally and ventrally extending the length of the fin. There are two black patches distally on the caudal fin central to the bands of yellowish-olive pigmentation. The pectoral fin is mostly hyaline with some yellowish pigmentation dorsally, and the pelvic fin is bright white.

PIGMENTATION IN PRESERVATIVE: Coloration in alcohol is shown in figure 3. Overall body coloration is tan to light brown with only faint remnants of the dorsal saddles, series of vertical bars below the lateral midline, and spots at the caudal base remaining in preservative. Additionally, a large black blotch is present posterior to the orbit and another smaller black blotch is present dorsally on the preopercle. All remaining faint markings are black or dark brown in coloration. All other former pigmentation has faded in preservation.

DISTRIBUTION: Known only from a single specimen collected by an ROV-based rotenone fish sampler (fig. 1A) at a depth of 187 m in the Western Province of the Solomon Islands near Peava Island, just outside of Peava Lagoon (8°47′03.3″S 158°14′08.7″E). The specimen was collected on a mostly barren rocky outcropping surrounded by sandy substrate and rubble, where other mesophotic/rariphotic species, were also observed and collected (fig. 1B). Additional individuals of the new species were observed at this locality, but could not be collected.

ETYMOLOGY: Named in reference to the characteristic pigmentation pattern on the upper flank comprising well-defined dark saddles that are continuous (i.e., connected) ventrally along the lateral midline, and that have a central (= dorsomedial) white spot, such that they resemble wheels (Latin = rota).