This species is distinguished from all other species of the genus, except S. maunaloae, by the following combination of characters: segmented rays in anal fin 7, tubed lateral-line scales 45-50, total gillrakers on first gill arch 31-34 (9 or 10 + 22-24), sum of lateral-line scales and gillrakers on individual specimens 77-84, depth of body 22.5-24.7 % SL (4.0–4.4 times in SL), length of depressed anal fin 24.8-26.4 % SL, hypurals 1 & 2 autogenous, hypurals 3 & 4 represented by a single plate, and first caudal vertebra without parapophyses. It can be separated from S. maunaloae by differences in mean numbers of tubed lateral-line scales (mean = 47.89 for S. parini vs. mean = 44.94 for S. maunaloae; and pectoral-fin rays (mean = 16.90 for S. parini vs. mean = 16.13 for S. maunaloae; and by differences in certain morphometric characters.