Author: (Chan, 1966)
Field Marks:
A deepwater, soft-bodied, plain catshark with a moderately short snout, first dorsal origin about opposite last half of pelvic bases, second dorsal larger than first, crest of denticles on dorsal and preventral caudal margins.
Diagnostic Features:
Snout narrowly rounded; nasal flaps small and angularly pointed; gill septa excavated and concave posteriorly. First dorsal fin considerably smaller than second; first dorsal origin opposite last half of pelvic bases or over pelvic insertions; first dorsal insertion far behind pelvic insertions; second dorsal about as large as anal fin; second dorsal origin far behind anal origin; second dorsal insertion far behind anal insertion; ventral edge of caudal peduncle and preventral caudal margin with a partial crest of enlarged denticles.
Geographical Distribution:
Western North Pacific: South China Sea.
Habitat and Biology:
A poorly known deepwater bottomdwelling shark from the upper continental slopes off China, on mud bottom at depths of 549 to 810 m.
Size:
Maximum 85 cm (female, possibly adult).
Interest to Fisheries:
None.
Remarks:
Chu et al. (1983) recently described Figaro piceus from the South China Sea at 19°40'N, 115°E, 810 m (holotype, 85 cmpand 19°03'N, 113°27'E, 660 m (paratype, 46 cm). They distinguished this species from P. melanobranchius by its longer predorsal space (greater than first dorsal origin to caudal tip in piceus, less in melanobranchius), shorter caudal fin (distance from second dorsal insertion to caudal tip about 4.5 in piceus, 3.4 in melanobranchius as examined by the writer), and colour (uniform blackish brown versus light brown with blackishbrown distal parts and anterior margins of fins, snout tip, nostrils, and gills in melanobranchius). Unfortunately, the first two characters are much influenced by growth in scyliorhinids, and may merely indicate changes in proportions within a species (the holotype of melanobranchius being much smaller than the two piceus types). Changes in coloration with growth are also known for some deepwater scyliorhinids, such as Holohalaelurus regani. Chu et al. stated that their new species differed from the present one in having only the last 2 (rather than, last 4) gill slits over the pectoral bases, but examination of the holotype of melanobranchius revealed the same condition as in piceus.
The writer is inclined to include Figaro piceus in tentative synonymy of the present species because of their general similarity in morphology, but notes that the first dorsal origin as pictured for piceus is about over the last half of the anal base, but is about over its insertion in the holotype of melanobranchius. This may or may not be significant, particularly as only 3 specimens of these sharks are currently known and it is uncertain how variable they are in this feature. The illustration is taken from the holotype of melanobranchius.
Type material:
Holotype: British Museum (Natural History), BMNH 1965.8.11.6, 235 mm immature female. Type Locality: 20°05'N, 115 03'E, 549 m depth.