Cephaloscyllium Gill 1862

Schaaf-Da, Jayna A. & Ebert, David A., 2008, A revision of the western North Pacific swellsharks, genus Cephaloscyllium Gill 1862 (Chondrichthyes: Carcharhiniformes: Scyliorhinidae), including descriptions of two new species, Zootaxa 1872, pp. 1-28 : 3

Cephaloscyllium Gill 1862

Scyliorhinus Blainville 1816: 121 .

Cephaloscyllium Gill 1862: 407 , 408.

Type species. Scyllium laticeps Dumeril 1853 , by original designation.

Diagnosis. Body stocky, stout, and spindle-shaped; firm and thick-skinned; with well-calcified dermal denticles. Head very depressed, flattened, and broad; narrowly rounded in lateral view; head short, bluntly pointed in lateral view; supraorbital crest of the chondrocranium present. Snout very short, rounded-parabolic shape in dorsoventral view; nostrils not enlarged; placed ventrally and hidden in lateral view; anterior nasal flaps broadly triangular to lobate, lacking barbels, positioned just anterior to mouth or reaching it; nasoral grooves absent; ampullae not greatly enlarged on snout. Eyes cat-like, dorsolateral on head. Mouth broadly arched; very large and wide; lacking upper and lower labial furrows; lower symphysis usually behind upper; appears to have a slight overbite in lateral view; upper teeth exposed in ventral view. First dorsal fin originates posterior to pelvic-fin origin; larger than the second dorsal fin. Second dorsal-fin originates over or slightly posterior to anal-fin origin. Pectoral fins large, somewhat rounded. Anal fin moderately large, smaller than pelvic and first dorsal fins; larger than second dorsal. Caudal fin broad and short, between a fourth and a fifth of the TL in adults. Coloration varies widely from beige to brown or uniform grey background, with darkly pigmented to obscure dorsal saddles numbering 4–9, blotches (sometimes blotches inside saddles), reticulated dark lines, or numerous blotches of dark brown to crème in addition to the dorsal saddles. Possess the ability to inflate the stomach with water or air to give a balloon-like, almost spherical shape to the trunk. Teeth, similar in upper and lower jaws, relatively small and numerous; each tooth has a high central cusp and one or two lateral cusplets on either side; number of tooth rows in either upper or lower jaws range from 48–85 in the different species.

Common name. Swellsharks or balloon sharks, refers to the ability to inflate the body by swallowing water or air.

Distribution. Swellsharks inhabit continental and oceanic insular waters of the temperate to sub-tropical Indo-Pacific ( Inoue & Nakaya 2006). They range in depth from the subtidal to the uppermost continental slope (~ 670 m).

Etymology. The generic name derives from the Greek kephale, meaning head, and skylion, meaning dogfish.