 This shark has a slender, cigar-shaped body with a sizable conical snout, a long but low second dorsal fin, and an almost symmetrical caudal fin.Its sister species "S. aliae" and it are the only sharks with a spine on the first dorsal fin and not the second.Spined pygmy sharks are dark brown to black, with numerous bioluminescent organs called photophores on their ventral surface.