Urolophus marmoratus Chu, Hu & Li, 1981

White, William T. & Last, Peter R., 2013, Notes on shark and ray types at the South China Sea Fisheries Research Institute (SCSFRI) in Guangzhou, China, Zootaxa 3752 (1), pp. 228-248 : 238

Urolophus marmoratus Chu, Hu & Li, 1981

[= Plesiobatis daviesi ( Wallace, 1967) ]

( Figure 14 )

Urolophus marmoratus Chu, Hu & Li in Chu, Meng, Hu & Li, 1981: 108, fig. (South China Sea).

Material examined. SCSFRI N 0428 (holotype), female 742 mm TL, South China Sea, depth 462 m, 5 Jun 1980 .

Remarks. Described by Chu, Hu & Li in Chu et al. (1981) based on four specimens collected from the South China Sea. However, the name is objectively invalid, being preoccupied by Urolophus marmoratus Philippi, 1892 which is now recognised as Urobatis marmoratus ( Philippi, 1892) . Thus, Urolophus marmoratus Chu, Hu & Li, 1981 is a junior homonym. In most cases, the junior homonym must be replaced with a new name if considered to be a valid taxon. The exception to this is if the two names are now placed under two different families, as with these two names, in which case it might not be necessary to give a replacement name (Article 23.9.5 of the International Code for Zoological Nomenclature, ICZN). Examination of the holotype of U. marmoratus at the SCSFRI ichthyological collection revealed that this specimen refers to Plesiobatis daviesi ( Wallace, 1967) . This species belongs to the monotypic family Plesiobatidae , but originally was placed in the family Urolophidae . Members of these two families are superficially similar in their possession of a distinct caudal fin, but Plesiobatis daviesi differs from urolophids (and urotrygonids) in having a very long snout (>6 times orbit diameter) and the dorsal surface covered with very small close-set denticles (vs. completely smooth) ( Last & Stevens, 2009). The caudal fin is also far more elongate in P. daviesi than in urolophids, and it attains a far larger size (> 2000 mm TL vs. <900 mm TL). Thus, Urolophus marmoratus of Chu, Hu & Li, 1981 is considered to be conspecific with Plesiobatis daviesi ( Wallace, 1967) but the combination is objectively invalid.

Figures

FIGURE 14. Dorsal view of the holotype of Urolophus marmoratus SCSFRI N 0428 (female 742 mm TL).