Longfin Flathead

description

Description. Dorsal fin rays I + VIII + I- 11 (I + VII or VIII + I- 11, or I + IX + 0 - 11, VII in one, IX in one); anal fin rays 12; pectoral fin rays 2 + 11 + 7 = 20 (2 + 10 or 11 + 6 – 9 = 19 – 21); pelvic fin rays I, 5; branched caudal fin rays 13 (12 or 13); scales in lateral line 55 (52 – 55), anterior four (3 – 5) scales with spine; posteroventrally slanted oblique scale rows above lateral line 83 (71 – 76); anteroventrally slanted oblique scale rows above lateral line 98 (91 – 104); gill rakers 1 + 7 = 8 (1 + 7 or 8 = 8 or 9). See table 1 for selected proportional measurements. Head length 2.7 (2.4 – 2.6) in SL. Snout rather robust, its length 3.2 in HL (3.1 – 3.2 in HL, slightly decreasing proportionally with growth, fig. 9). Iris lappet broad and simple both dorsally and ventrally (fig. 5 d). Interorbital width 13.9 (12.5 – 16.7) in HL. Nasal bone without distinct spines, but with tubercles (fig. 4 d). Lachrymal with three anterolaterally directed spines on left side, right side partly damaged (2 – 5, with short serrations posterior to spines in some paratypes). Single preocular spine in front of eye, its base with tubercles (with small spines in several paratypes). Subor

Taxonomic revision of the genus Ratabulus (Teleostei: Platycephalidae), with descriptions of two new species from Australia

diagnosis

Diagnosis. A species of Ratabulus with 91 – 104 anteroventrally slanted oblique scale rows above lateral line; snout length 30.9 – 32.4 % HL, markedly decreasing proportionally with growth; pectoral fin length 15.8 – 18.6 % SL; pelvic fin length 26.2 – 28.2 % SL; nasal bone with tubercles; dorsal surface of head with small, round, brown spots, body without dark spots; pelvic fin with small brown spots.

Taxonomic revision of the genus Ratabulus (Teleostei: Platycephalidae), with descriptions of two new species from Australia

discussion

Remarks. R. ventralis is most similar to R. diversidens, from which it can be distinguished as discussed in ‘ Remarks’ in the above treatment of the latter. This species is poorly represented in museum collections and has been mostly overlooked in the literature. It has been considered by authors, which have treated specimens, as simply northern records of R. diversidens.

Taxonomic revision of the genus Ratabulus (Teleostei: Platycephalidae), with descriptions of two new species from Australia

distribution

Distribution. Northeastern Australia from Townsville (17 ° 51 ' S) to Noosa, Queensland (26.25 ° S), at depths of at least 120 – 366 m (fig. 1).

Taxonomic revision of the genus Ratabulus (Teleostei: Platycephalidae), with descriptions of two new species from Australia