Liopropoma santi, Baldwin, Carole C. & Robertson, D. Ross, 2014

Baldwin, Carole C. & Robertson, D. Ross, 2014, A new Liopropoma sea bass (Serranidae, Epinephelinae, Liopropomini) from deep reefs off Curacao, southern Caribbean, with comments on depth distributions of western Atlantic liopropomins, ZooKeys 409, pp. 71-92 : 73-82

Liopropoma santi sp. n. Figs 2-4, Spot-tail Golden Bass

Type locality.

Curaçao, southern Caribbean

Holotype.

USNM 426811, 116 mm SL, DNA #CUR 13253, Curasub submersible, sta. 13-14, southern Caribbean, Curaçao, off Substation Curaçao downline, near 12°05.069'N, 68°53.886'W, 241 m, quinaldine, 9 Aug 2013, C. C. Baldwin, D. R. Robertson, A. Driskell, B. van Bebber.

Paratypes. USNM 426813, 76.2 mm SL, DNA #CUR 13280, Curasub submersible, sta. 13-19, southern Caribbean, Curaçao, Playa Forti, Westpoint, 12°22.001'N, 69° 9.005 W, 182 m, quinaldine, 15 Aug 2013, A. Schrier, N. Knowlton, R. Sant, B. van Bebber. USNM 414824, 42.0 mm SL, DNA #CUR 12314, Curasub submersible, sta. 12-19, southern Caribbean, Curaçao, east of Substation Curaçao downline, near 12°05.069'N, 68°53.886'W, 209 m, 15 Aug 2012, C. C. Baldwin, B. Brandt, B. van Bebber.

Diagnosis.

A liopropomin serranid with the following combination of characters: dorsal fin VIII,13; anal fin III, 8; pectoral fin 15; total gill rakers on first arch (including rudiments) 20-21; lateral-line scales 47-48; length of first dorsal spine 2.9-4.2% SL; margin of spinous dorsal fin moderately indented posteriorly in adults (fourth spine 11-12% SL, fifth and sixth spines only slightly shorter than fourth-6.9-10% SL); depth at origin of dorsal fin 23-26% SL; least depth of caudal peduncle 11-13% SL; orbit diameter 9.4-12% SL; yellow-orange stripe externally on upper lip; series of approximately 13 white, chevron-shaped markings on ventral portion of trunk; reddish-black blotch on distal portion of lower caudal-fin lobe; inhabiting depths of 182-241 m.

Description.

Counts and measurements of holotype, if different from those of paratypes, are given in parentheses. Dorsal-fin rays VIII, 13; anal-fin rays III, 8; pectoral-fin rays (both sides) 15; pelvic-fin rays I, 5; principal caudal-fin rays 9+8=17; procurrent caudal-fin rays 9+9=18; pored lateral-line scales 48 (47), two additional pored scales present on base of caudal fin not included in total count; scales from lateral line to dorsal-fin origin 3 or 4 (3); gillrakers on first arch, including rudiments, 6+14-15 (6+14); upper limb with 3 rudiments + 3 rakers, lower limb with 11-13 rakers + 2-3 rudiments, total 20-21 (20); vertebrae 10 + 14.

Body proportions expressed as percentage of SL. Body depth at origin of dorsal fin 23-26 (26); body width just behind gill opening 11-14 (14); head length 37-39 (37); snout length 7.4-9.1 (9.1), relative length increasing with increasing SL; orbit diameter 9.4-12 (9.4) relative diameter decreasing with increasing SL; bony interorbital width 4.5-5.5 (5.5); upper-jaw length 16-18 (18); greatest depth of maxilla 5.0-6.1 (6.1); least caudal-peduncle depth 11-13 (13); caudal-peduncle length 22-24 (23); lengths of dorsal-fin spines: (I) 2.9-4.2 (4.2); (II) 11-12 (12); (III) 13-15 (14); (IV) 11-12 (11); (V) 6.9-10 (10); (VI) 6.9-8.2 (8.2); (VII) 5.0-7.5 (7.5); (VIII) 4.8-6.9 (6.9); longest dorsal soft ray the 11th, length 15-20 (20); length of 3rd anal-fin spine 6.9-9.3 (9.3); longest anal soft ray the 5th, length 15-17 (16); caudal-fin length 23-28 (23), relative length decreasing with increasing SL; pectoral-fin length 27-30 (27), fin reaching vertical between anus and origin of anal fin, falling short of anal fin in all specimens; pelvic-fin length 18-20 (19), fin reaching vertical through base of 6th dorsal-fin spine, well short of anus.

Interorbital region flat to slightly convex; mouth oblique, maxilla reaching vertical beyond posterior border of pupil; prominent bony projection on posteroventral corner of maxilla; lower jaw slightly projecting. Anterior nostril in thin, membranous tube, nostril situated just posterior to groove between tip of snout and premaxilla; posterior nostril a simple opening, nostril situated close to orbit (the distance approximately 1.5 nostril diameters). Lateral line strongly arched above pectoral fin, highest point below fourth and fifth dorsal-fin spines.

Trunk covered with ctenoid scales, scales becoming weakly ctenoid anteriorly and cycloid on head. Head fully scaled except over branchiostegal area. Holotype with short column of scales on dorsal-fin spines III and IV, scales on basal portion of membranes between spines VI and VIII, three rows of scales covering basal portion of soft dorsal fin, and some scales extending distally onto soft dorsal-fin membranes; paratypes with same squamation except no scales present on spinous dorsal fin, and 42.0-mm SL paratype having only basal scale rows on soft dorsal fin. In holotype and larger paratype, anal fin with two or three rows of scales basally and additional scales that extend distally onto fin membranes and cover most of fin. In smaller paratype, scales confined to basal portion of fin. Caudal fin completely scaled in holotype except for distal tips of rays; larger paratype with scales covering only proximal half of fin; smaller paratype with scales confined to basal portion of fin. Scales present on pectoral-fin base, and elongate scales present on proximal portion of fin. Scales present on pelvic-fin base and on proximal portion of fin; pelvic axillary scales present.

Jaw teeth small and depressible; upper and lower jaws with bands of villiform teeth, bands widest anteriorly, largest teeth in innermost row. Vomer with a chevron-shaped patch of small teeth. Palatines with several rows of small teeth in a long, narrow band. Opercle with three flattened spines, only the middle one conspicuous. Margin of upper limb of preopercle and angle with small serrations, lower limb smooth.

Prior to preservation (Figs 2, 3), background color of upper portions of trunk and caudal peduncle yellow, grading to pale pink around midbody, then to white ventrally; no abrupt transitions between those colors; many individual scales on upper half of body marked with orange spots in adults, densely so in holotype; a series of about 13 narrow, bright-white, chevron-shaped bars that point posteriorly present on lower half of trunk, series extending from just behind pectoral-fin base to vertical through center or posterior portion of anal fin; upper arms of white bars more strongly defined; nape yellow from dorsal midline ventrally to about mid-eye level (with some orange spots on scales in adults), grading anteriorly into an irregularly shaped area of purplish-pink over and behind eye, on upper portion of iris, and on snout; a yellow blotch present behind center of eye (in adults) and a smaller one present on dorsal midline of snout just anterior to orbit; iris mostly orange-yellow, grading to fine inner yellow ring; prominent, mostly deep-yellow (adults) or mostly orange (juvenile) stripe along outside of entire upper lip, this pigment spreading slightly above lip along anterior half of jaw in adults and merging with the pink/orange pigment on snout of juvenile; inside of lower lip with small blotch of yellow pigment in adults, inside of upper lip with stripe of yellow (adults) or orange (juvenile); photographic angle did not permit characterization of pigment on inside of lower lip of juvenile; lower jaw and lower two thirds of head white, with pinkish cast in holotype; in adults, dorsal fin with yellow spines and mostly white inter-spinous membranes; soft dorsal-fin rays yellow, membrane between anterior rays yellow, and membrane between rays of remainder of fin with small to large pale area centrally, size of pale area increasing posteriorly such that membrane between posteriormost rays completely pale; some rays and membranes in posterior portion of soft dorsal fin with pale rose pigment in smaller adult; a thin white margin extending along outer edge of entire dorsal fin, this margin appearing blue-white when fish photographed against black background (Fig. 3); in juvenile, inter-spinous membranes of dorsal fin mostly pale and soft dorsal mostly pale except for yellow stripe at the base and yellow stripe near outer margin of fin; caudal fin mostly yellow in holotype, central portion of fin with pale outer margin and with pale to pinkish-orange membranes between rays; thin pinkish-orange stripe present along dorsal and ventral margins of fin; distal tip of lower lobe with reddish-black blotch, a few thin streaks of black extending proximally from this blotch; pigment on caudal fin of smaller adult similar but with less pinkish-orange pigment, and caudal fin of juvenile mostly clear with a large, oval-shaped, oblique yellow blotch on outer half of both upper and lower lobes; dark spot on distal portion of ventral caudal lobe relatively larger in juvenile; anal fin white, with faint pinkish-yellow streak on first through fifth rays in holotype, little or no color in smaller adult and juvenile; pelvic fin white; pectoral fin translucent with pale pinkish-orange cast; general coloration most intense in the holotype and least intense in the juvenile.

In alcohol (see Fig. 6A), body pale, the only pigment a dark blotch on distal tip of ventral caudal-fin lobe.

Distribution.

Known only from Curaçao, southern Caribbean.

Habitat.

Off Curaçao, Liopropoma santi is found from 182-241 m inhabiting rocky slopes and ledges. It retreats into small caves and crevices when approached and illuminated by the submersible. Figure 4 shows an in-situ photograph taken from the Curasub submersible at 204 m on a reef slope off Jan Theil Bay, Curaçao.

Etymology.

The specific name honors Roger Sant, who participated in the Curasub submersible dive at Playa Forti during which the USNM 426813 paratype was collected. Roger and Victoria Sant have provided generous funding to the Smithsonian Institution’s National Museum of Natural History for ocean-related activities.

Common name.

"Spot-tail golden bass" is in reference to the dark spot on the lower lobe of the caudal fin, which, along with other characters, distinguishes Liopropoma santi from the two other species of western Atlantic Liopropoma that have predominantly golden coloration, Liopropoma aberrans and Liopropoma olneyi .

Comparisons.

Counts and measurements of the three western Atlantic "golden basses" collected off Curaçao, Liopropoma santi , Liopropoma aberrans , and Liopropoma olneyi , are given in Table 2, representative images of the three are provided in Figure 5, and a summary of major differences among them appears in Table 3. An image of a freshly collected specimen of a species of the related genus Bathyanthias is also included in Figure 5 for comparative purposes. Liopropoma santi is easily distinguished from the others by color in life, especially by the presence of a yellow or orange stripe externally on the upper lip, a series of white chevron-shaped markings on the ventral portion of the trunk, and the reddish-black blotch on the distal portion of the lower caudal-fin lobe. The last also visually distinguishes Liopropoma santi from Liopropoma aberrans and Liopropoma olneyi in preservative. Liopropoma santi is further distinguished from both of those species by having more dorsal-fin rays, more gill rakers on the first arch, and usually a larger eye (Table 2). From Liopropoma aberrans , Liopropoma santi is further distinguished by having more pectoral-fin rays, a narrower body at the dorsal-fin origin, a narrower caudal peduncle, longer fourth-sixth dorsal-fin spines, and a more shallow indentation in the spinous dorsal fin (Tables 2, 3).

Baldwin and Johnson (2014) discussed the status of Liopropoma aberrans , which was described from a single specimen collected off Cuba in the 19th century ( Poey 1860) and redescribed from a single specimen collected off the Bahamas in the 20th century ( Robins 1967). They noted differences in the descriptions of color patterns of the two specimens and numbers of dorsal-fin rays (IX, 12 in Poey’s Liopropoma aberrans , VIII, 12 in Robins’ Liopropoma aberrans ), and they questioned whether or not the two specimens represent the same species. Specimens of Liopropoma aberrans collected off Curaçao ( “Curaçao Liopropoma aberrans ") share with the Bahamas Liopropoma aberrans the same dorsal-fin count, general body shape, and color pattern, although Baldwin and Johnson (2014) noted some differences in the color pattern. Curaçao Liopropoma aberrans have 17-18 gill rakers on the first arch (Table 2), whereas Robins (1967) reported 14 for the Bahamas specimen; however, as noted by Baldwin and Johnson (2014), Robins’ count only included the rudimentary pads on the upper limb. Examination of the Robins’ Bahamas specimen (UMML 22324) indicates that there are four rudimentary pads on the lower limb, and thus the total number of gill rakers on the first arch is 18.

Curaçao and Bahamas Liopropoma aberrans , however, appear to have different depth preferences, with Robins’ Liopropoma aberrans occurring deeper-229 m. At Curaçao, Liopropoma aberrans was collected between 98 and149 m and observed by us only within that depth range during nearly 100 submersible dives over a three-year period. This is unlikely to be due to effects of differences in habitat availability at the two locations, as Liopropoma santi and Liopropoma olneyi occur at deeper depths than Liopropoma aberrans at Curaçao.

Poey (1860) did not provide depth data or a gill-raker count for his 115-mm SL specimen from Cuba. Curaçao Liopropoma aberrans differs from the Cuban Liopropoma aberrans in dorsal-fin count and certain aspects of color pattern, but fish from those two sites share the presence of yellow spots on the cheek (sometimes lacking in juvenile Curaçao Liopropoma aberrans ), spots that were not mentioned by Robins (1967) for the 112-mm SL Bahamas Liopropoma aberrans . The whereabouts of the holotype of Liopropoma aberrans are unknown ( Eschmeyer 2013), and, in the absence of additional material from the type locality for comparative purposes, we follow Baldwin and Johnson (2014) in tentatively recognizing the specimens from Cuba, Bahamas, and Curaçao as Liopropoma aberrans . As noted by Baldwin and Johnson (2014), a digitized copy of a color photograph of a specimen of Liopropoma aberrans from Jamaica taken and provided by Patrick Colin shows a color pattern nearly identical to that of Curaçao Liopropoma aberrans . Should Poey’s Liopropoma aberrans prove to be distinct from specimens from the Bahamas, Curaçao, and Jamaica, one or more new species will need to be recognized.

Liopropoma santi differs from Poey’s and Robins’ Liopropoma aberrans in number of dorsal-fin rays (VIII, 13 vs. IX, 12 and VIII, 12, respectively) and shape of dorsal fin (with only a moderate indentation in spinous dorsal fin in Liopropoma santi , deep indentation in the others). It further differs from Robins’ Liopropoma aberrans in numbers of pectoral-fin rays (15 vs. 14) and gill rakers on the first arch (20-21 vs. 17-18), and color pattern (presence of diagnostic color features of Liopropoma santi -see Diagnosis–vs. absence). From other western Atlantic Liopropoma ( Liopropoma carmabi [ Randall 1963], Liopropoma eukrines [ Starck and Courtenay 1962], Liopropoma mowbrayi [ Woods and Kanazawa 1951], Liopropoma rubre Poey 1861), Liopropoma santi differs most notably in color pattern (Fig. 1) and in having VIII, 13 dorsal-fin rays (vs. VIII, 12 in all except one specimen of Liopropoma carmabi with VIII, 13-Table 4).

Counts of Liopropoma santi closely match those of Bathyanthias cubensis ( Schultz 1958) in having VIII, 13 dorsal-fin rays; III, 8 anal-fin rays; 15 pectoral-fin rays; and 20-21 gill rakers on the first arch. Liopropoma santi has 47-49 lateral-line scales, whereas Bathyanthias cubensis has 46-47. The two species are otherwise very different. Liopropoma santi has a shallower trunk (body depth 23-26% SL and caudal-peduncle depth 11-13% SL in Liopropoma santi vs. 28-32% SL and 14-15% SL, respectively, in Bathyanthias cubensis - Schultz 1958), and Liopropoma santi has a single blotch of dark pigment on the distal portion of the lower caudal-fin lobe vs. dark pigment on the distal ends of all caudal-fin rays. Like other species of Bathyanthias , the dorsal profile of the head in Bathyanthias cubensis is convex (vs. usually straight in Liopropoma -although there may be a bump on the snout and the profile may be slightly convex in large specimens of Liopropoma ); there is little indentation in the margin of the spinous dorsal fin (vs. larger indentation); the posteroventral corner of the maxilla has a weakly developed hook-like process (vs. well developed in Liopropoma -see Randall and Taylor [1988] and Baldwin and Johnson [1993]); and in Bathyanthias , the anterior portion of the lateral line is broadly curved over the pectoral fin (vs. sharply curved in Liopropoma ). Differences between Liopropoma santi and Liopropoma cubensis can be seen in Figure 6, and the generic characters listed above can be seen in Figures 5 and 6. The depth range of Bathyanthias cubensis is greater than that of Liopropoma santi , 183-411 m vs. 182-241 m.