Ratabulus fulviguttatus, Imamura & Gomon, 2010

Imamura, Hisashi & Gomon, Martin F., 2010, Taxonomic revision of the genus Ratabulus (Teleostei: Platycephalidae), with descriptions of two new species from Australia, Memoirs of Museum Victoria 67, pp. 19-33 : 29-31

publication ID	https://doi.org/ 10.24199/j.mmv.2010.67.03
publication LSID	lsid:zoobank.org:pub:D288CCCE-F0C7-4D7B-A19E-B0D99D360BF8
DOI	https://doi.org/10.5281/zenodo.10879372
persistent identifier	https://treatment.plazi.org/id/4A057A6D-3359-7048-3305-F98FFE8FFD3B
treatment provided by	Felipe
scientific name	Ratabulus fulviguttatus
status	sp. nov.

Treatment

Ratabulus fulviguttatus View in CoL sp. nov.

English name: Orangefreckled flathead

( Figures 2c View Figure 2 , 3c View Figure 3 , 4c View Figure 4 , 5c View Figure 5 , 6c View Figure 6 , 8c View Figure 8 )

Ratabulus diversidens View in CoL (nec McCulloch, 1914): Gloerfelt-Tarp and Kailola, 1984: 123, unnumbered fig. (short description, northwestern Australia); Sainsbury et al., 1985: 114, unnumbered fig. (description, northwestern Australia); Paxton et al., 1989: 470 (list and distribution, Northwestern Shelf, Australia) (in part); Knapp, 1999:2410 (description, Northwestern Shelf and Timor Sea) (in part); Hutchins, 2001: 28 (list, Western Australia); Hoese et al., 2006: 944 (list and distribution, off North West Cape to off Port Hedland, Western Australia) (in part).

Holotype. CSIRO H 4031-79, 262 mm SL, north of Cape Lambert, Western Australia (18°57’S, 117°14’E), 248 m, 30 August 1995, FRV Southern Surveyor. GoogleMaps

Paratypes. 16 specimens (140-266 mm SL), from northwestern Australia. AMS I.21621-006, 206 mm SL, northwest shelf, Western Australia (11°49'S, 124°17'E), 195–200 m, 10 June 1979 GoogleMaps ; AMS I.22805-013, 3: 177–188 mm SL, 170 km north of Port Hedland , Western Australia (18°28'S, 118°15'E), 150–156 m, 28 March 1982 GoogleMaps , FRV Soela; AMS I.22807-023, 3: 188–227 mm SL, 175 km north of Port Hedland , Western Australia (18°32'S, 118°17'E), 200–204 m, 2 April 1982 GoogleMaps , FRV Soela; AMS I.22828-012, 3: 248–265 mm SL, 190 km north of Port Hedland , Western Australia (19°01'S, 117°12'E), 200–202 m, 14 April 1982 GoogleMaps , FRV Soela; CSIRO CA3624 (voucher of Sainsbury et al., 1985), 233 mm SL, northwest of Nichol Bay , Western Australia (19°15'S, 116°40'E), 172 m, 25 January 1983 GoogleMaps , FRV Soela; CSIRO CA 4091, 229 mm SL, north of Bathurst Island, Arafura Sea , Northern Territory (10°02'S, 130°01'E), 216 m, 8 July 1980 GoogleMaps ; CSIRO H 1035-23, 251 mm SL, north of Dampier Archipelago , Western Australia (19°08'S, 116°54'E), 196 m, 24 October 1996 GoogleMaps , FRV Soela; CSIRO H1512-04 View Materials , 140 mm SL, north of Monte Bello Islands , Western Australia (19°39'S, 115°36'E), 180 m, 11 October 1988 GoogleMaps , FRV Soela; CSIRO H 4031-79, 262 mm SL, north of Cape Lambert , Western Australia (18°57'S, 117°14'E), 248 m, 30 August 1995 GoogleMaps , FRV Southern Surveyor; CSIRO H4631-03 View Materials , 198 mm SL, north of Dampier Archipelago , Western Australia (19°11'S, 116°35'E), 196 m, 11 August 1997 GoogleMaps , FRV Southern Surveyor; WAM P.32204-001, 208 mm SL, Western Australia, Timor Sea (12°57'S, 124°20'E), 8 June 1979 GoogleMaps .

Nontypes. Two specimens. WAM P.9351-001, 76.0 mm SL, Western Australia (21°49'S, 113°56'E), 121–126 m, 1 February 1964; WAM GoogleMaps P. 9352-001, 77.1 mm SL, coll. with WAM P.9351-001.

Other material. Two specimens. CSIRO H1505-06 View Materials , 219 mm SL, north of Nickol Bay , Western Australia (19°07'S, 117°06'E – 19°07'S, 117°04'E), 177–184 m, 5 October 1988, FRV Soela; CSIRO H1505-06 View Materials , 189 mm SL, collected with CSIRO H1505-06 View Materials (used for description of color when fresh) GoogleMaps .

Diagnosis. A species of Ratabulus with 99–113 anteroventrally slanted oblique scale rows above lateral line; snout length 30.4–34.8% HL, markedly decreasing proportionally with growth; pectoral fin length 14.6–16.5% SL; pelvic fin length 20.9–25.7% SL; nasal bone without tubercles; dorsal surface of head and body pale brown, with small, round brown spots; and pelvic fin with small brown spots.

Description. Dorsal fin rays I + VIII + I-11 (I + VII to IX + I-11 or 12, VII in one and IX in one, 12 in one); anal fin rays 12 (11 or 12, 11 in one); pectoral fin rays 2 + 12 + 6 = 20 (1 or 2 + 9–12 + 6–8 = 19–21, usually 20); pelvic fin rays I, 5; branched caudal fin rays 13; scales in lateral line 56 (54–56), anterior three (three or four) scales with spine; posteroventrally slanted oblique scale rows above lateral line 80 (71–80); anteroventrally slanted oblique scale rows above lateral line 107 (99–113); gill rakers 1 + 7 = 8 (1 + 6–8 = 7–9, usually 7).

See table 1 for selected proportional measurements. Head length 2.6 (2.4–2.7) in SL. Snout rather slender, its length 3.3 (3.0–3.3) in HL, markedly decreasing proportionally with growth (fig. 9). Iris lappet broad and simple both dorsally and ventrally (fig. 5c). Interorbital width 16.3 (14.5–20.0) in HL. Nasal bone with small spine, but without tubercles (fig. 4C). Two spines on lachrymal of right side, three on left, spines directed anterolaterally. Single preocular spine in front of eye, its base without spines or tubercles (with tubercle on left side of one paratype, CSIRO H4631-03 View Materials ). Suborbital ridge with many small to large spines, anteriormost (preorbital) distinct. Supraorbital ridge serrated except anteriorly. Single postocular spine present. Pterotic with one spine (one to four spines). Parietal with single spine, without accompanied spines posteriorly (followed by one or two spines in several paratypes). Supratemporal with one spine (two to three spines in several paratypes). Posttemporal with one spine. Preopercle with two spines (three in several paratypes); upper longer, not reaching posterior margin of opercle, bearing one small spine on base laterally (rarely two spines or spines absent). Ridge of lower opercular spine without serrations. Posterior end of maxilla below anterior margin of pupil (not reaching to anterior margin of pupil in several paratypes). Anterior part of upper jaw with short canines at front, followed by long and slender canines posteriorly; middle and posterior parts of upper jaw with villiform teeth, innermost row comprising small, slender, conical teeth. Lower jaw with two tooth rows (one to about three rows); outer row with moderately long conical teeth anteriorly, and two rows of villiform teeth anterolaterally (outer one to two rows of villiform teeth, or small to moderately long conical teeth), teeth becoming smaller posteriorly, teeth villiform posteriorly; inner row with conical teeth (canines of small to moderate size in several paratypes). Palatine with moderately broad tooth band; anterior part of palatine with canines of moderate length (long canines in several paratypes) laterally, and long and slender canines mesially; posterior part of palatine with small to moderately long conical teeth. Vomer with about three tooth rows medially (with two to four rows), small canines anteriorly (canines of moderate length in several paratypes), followed by long, slender canines. Posterior margin of caudal fin slightly concave (mostly straight in several paratypes); fin length 6.0 (5.0–6.2) in SL. Pectoral fin length 6.1 (6.1–6.8) in SL. Posterior tip of pelvic fin not reaching anal fin origin (just reaching anal fin origin or just beyond it in several paratypes); pelvic fin length 4.3 (3.9–4.5) in SL.

Color in alcohol. Head and body pale brown dorsally, pale yellowish ventrally; dorsal surface of head and body with small, round, brown spots, but no bands; lateral side of body below lateral line with pale purple longitudinal stripe (or stripe formed by continuous series of purple spots). First dorsal fin with one dark grayish submarginal stripe, basal area clear anteriorly with scattered small dark-brown spots; second dorsal fin with brown (or dark brown) spots. Anal fin pale. Caudal fin with many black longitudinal narrow stripes and spots posteriorly; upper part of fin with several brown spots. Pectoral fin slightly dusky, with small brown spots. Pelvic fin mostly faded on left side, with few small indistinct brown spots on right (with several small distinct brown spots in several paratypes) (fig. 6c).

Color when fresh from photographs of CSIRO H505-15 and H505-16 (fig. 8c). Head and body with small, round, reddish brown and brown spots dorsally. Body with two broad brown bands dorsally. Other colors similar to those in alcohol.

Distribution. Northwestern Australia, from North West Cape, Western Australia (21°49'S) to Bathurst Island, Northern Territory (10°02'S), at depths of at least 126–248 m ( Sainsbury et al., 1985; Paxton et al., 1989) (fig. 1).

Etymology. The specific name fulviguttatus , from the Latin word meaning ‘orange or brown spots’, refers to this species’ characteristic spots on the head and body.

Remarks. R. fulviguttatus differs from R. ventralis in having the nasal bone without tubercles (versus with tubercles) (fig. 4), shorter pelvic fins (20.9–25.7% SL versus 25.3–28.2% SL) (fig. 11), and body with small, round, brown spots (versus without spots) (fig. 2). It is easily separable from R. diversidens , with which it has been confused, by the small, round, brown spots scattered over the dorsal surface of the head and body (versus without spots). The spots in R. fulviguttatus are reddish and/or brown when fresh, which explains the Australian standard name. The character is clearly evident in colour photos and description provided by Gloerfelt-Tarp and Kailola (1984) and Sainsbury et al. (1985).