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

Martin F. Gomon and Hisashi Imamura

Memoirs of Museum Victoria Vol 67 p. 19–34 (2010)

DOI
http://doi.org/10.24199/j.mmv.2010.67.03

Abstract

The platycephlid genus Ratabulus Jordan and Hubbs, 1925 is reviewed taxonomically. The genus is defined by the long, slender canines on its upper jaw, palatine and vomer, the presence of a small free spine between the two dorsal fins, the iris lappet broad and simple dorsally, the suborbital ridge with numerous spines, the suborbitals and preopercle lacking sensory tubes in the cheek region, and lateral line scales with only a single pore posteriorly. Although the genus has been regarded as comprising only a single species, Ratabulus diversidens (McCulloch, 1914), this study presents descriptions of four: R. megacephalus (Tanaka, 1917) in southern Japan to the South China Sea, R. diversidens in eastern Australia, R. fulviguttatus sp. nov. in northwestern Australia and R. ventralis sp. nov. in northeastern Australia. R. megacephalus, having been regarded as a junior synonym of R. diversidens, is easily separable from that species in having more anteroventrally slanted oblique scale rows above the lateral line (94–112 versus 80–93). R. fulviguttatus sp. nov. is similar to R. megacephalus in having small dark spots dorsally on the body, but differs from it in having a shorter snout (30.4–34.8% HL versus 31.2–35.7% HL), longer pelvic fin (20.9–25.7% SL versus 19.5–23.1% SL), and a pale brown head and body (versus dark brown). Although R. ventralis sp. nov. resembles R. diversidens in having the nasal bone with tubercles, the former is distinguished from the latter and R. megacephalus by its longer pectoral fin (15.8–18.6% SL versus 13.9–17.0%SL). R. diversidens also differs from its three congeners in having larger brownish spots on the pelvic fin.

Citation

Gomon, M.F. & Imamura, H., 2010. Taxonomic revision of the genus Ratabulus (Teleostei: Platycephalidae), with descriptions of two new species from Australia. Memoirs of Museum Victoria 67: 19-34. http://doi.org/10.24199/j.mmv.2010.67.03

PUBLICATION DATE: 14 December 2010

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