Author: (Bonnaterre, 1788)
Field Marks:
A catshark with a stout body, no labial furrows, and with a striking colour pattern of dark dorsal saddles, lateral blotches, and small to moderately large dark spots on light ground colour, anterior nasal flaps short, subtriangular, and not overlapping mouth posteriorly, and second dorsal fin much smaller than first.
Diagnostic Features:
Snout broadly rounded-angular in dorsoventral view, rather short and broad; anterior nasal flaps subtriangular, not overlapping mouth posteriorly. Claspers short and stout. Colour pattern variegated, with up to 11 dark brown irregular saddles and laterally interdigitating blotches in a checkerboard pattern in the typical New Zealand form, but with more irregular dark blotches and mottling in Taiwanese and Japanese representatives of the species (if not distinct); a scattering of numerous dark brown or blackish small spots on a grey or brown background; underside of head and abdomen unspotted; fins without conspicuous light margins. A large species (see size below).
Geographical Distribution:
Western Pacific: New Zealand, China (Taiwan Island) and Japan (southeastern Honshu).
Habitat and Biology:
A common, sluggish inshore and offshore warm-temperate catshark found on rocky and sandy bottoms in deepish water on the continental and insular shelves, at depths of 18 to 220 m; said to avoid open areas but favours reefs. Can expand itself with air or water. Oviparous. Eats crabs, worms and other invertebrates, and probably bony fishes.
Size:
Maximum 92 to 100 ffi cm, said to reach 244 cm off New Zealand but possibly due to confusion with some other shark, such as Notorynchus cepedianus; adult males 69+ cm; adult females 86 cm.
Interest to Fisheries:
None or limited at present, caught by commercial bottom trawlers.
Remarks:
As noted in the generic remarks, above, the synonymy of this species is tentative, and follows Springer (1979). The holotype of Cephaloscyllium umbratile in the Stanford University collections (a 95 cm adult male specimen, SU 12693, preserved as a skin according to Jordan and Fowler, 1904), could not be located by Springer (1979) or the writer, and is presumed lost. Several writers, including Teng (1962), Chen (1963), Fourmanoir and Nhu-Nhung (1965), Chan (1966), Bessednov (1969), and Nakaya (1975) have reported a species of Cephaloscyllium from Viet Nam, China, (including Taiwan Island) and Japan as C. umbratile. This apparently differs from C. isabellum (or C. umbratile-formosanum, if distinct) in its smaller size at maturity (adult males 39 to 42 cm, females at 36 to 42 cm, versus isabellum at over 60 cm), colour pattern of indistinct dusky saddles and blotches without small spots and mottling, longer snout, and more elongated nasal flaps. Comparison of Jordan and Fowler's (1904) original description of C. umbratile with Teng's (1962) accounts of C. umbratile and C. formosanum suggests that the latter writer renamed the true large umbratile as C. formosanum in the belief that the small species was umbratile. The writer has examined specimens of the small "umbratile" from off Hong Kong and suspects that these represent an undescribed species of dwarf swellshark, not conspecific with the other small species C. silasi and C. fasciatum.
Type material:
Holotype: Apparently lost, according to Springer (1979). Type Locality: "La mer du sud".