Identifying traits of this species include the spiracles, which are more widely spaced than the eyes and bear papillae (nipple-shaped structures) on the posterior inner rims, and the relative positions of the two dorsal fins.

Additionally, S. caillieti lacks fringes on its barbels, enlarged thorns along the middle of its back, and ocelli ("eyespots") on its fins.

It was originally identified tentatively as a Taiwan angelshark (S. formosa), before being described as a new species by Jonathan Walsh, David Ebert, and Leonard Compagno in a 2011 issue of the scientific journal Zootaxa.

[2] Like other angel sharks, S. caillieti has a flattened, ray-like form with greatly enlarged pectoral and pelvic fins.

The large nostrils are teardrop-shaped and preceded by flaps of skin enlarged into two cylindrical barbels that overhang the mouth.

The mouth is wide and terminally placed on the snout, with furrows at the corners and the center of the upper lip forming a rounded arch.