This species is distinguished from its congeners in SW Atlantic by the following characters: color pattern with randomly and asymmetrically distributed black and white spots of varied sizes (predominantly small) (vs. spots predominantly within saddles and with approximate bilateral symmetry in S. haeckelii, S. ugoi); saddles not well defined and without sharp median projections (vs. well-defined saddles in S. haeckelii and saddles with sharp median projections in S. ugoi); claspers with a well-developed groove on the terminal portion of the ventral terminal cartilage (vs. absent or undeveloped groove in S. haeckelii, S. ugoi); no envelope and poorly developed exorhipidion (vs. with envelope and developed exorhipidion in S. haeckelii); neurocranium with a proportionately broader basal plate (vs. narrow basal plate in S. haeckelii, S. ugoi); other characters, although less conspicuous, also distinguishes these species: small and rounded snout, mean preoral length 5% TL (vs. mean 4.5% TL in S. haeckelii); moderately broad and depressed head with its length 19.7-20.8% TL (vs. 17.5-19.2% TL in S. haeckelii); first dorsal fin triangular, never subrectangular (vs. sometimes subrectangular in S. haeckelii); interdorsal space 2 times dorsal-caudal space (vs. 1.2-2 times in S. haeckelii, 2.1-2.5 in S. ugoi); ventral terminal 2 cartilage slender, positioned on ventral terminal cartilage, 1.5 times length of ventral terminal cartilage (vs. 1.8 times in S. haeckelii); components of clasper proportionately larger than in S. haeckelii; somewhat small sized adult males, about 39.3 cm TL, and adult females, at least 42.0 cm TL (vs. 44.5 cm and 50.0 cm TL, respectively, in S. ugoi) (Ref. .107325).