The Indo-Pacific anthiine fish genus Luzonichthys Herre, characterized by a slender body, fully divided dorsal fin, 2 opercular spines, 11 + 15 vertebrae, and small size (total length less than 7 cm) is represented by the following 6 species: L. earlei Randall, L. microlepis (Smith), L. waitei (Fowler), L. whitleyi Smith, L. taeniatus, n. sp., and L. williamsi, n. sp.
L. earlei is distinctive in having modally 20 pectoral rays and 59-68 lateral-line scales. L. microlepis has II,9 anal rays, usually 22 or 23 pectoral rays, 70-76 lateral-line scales, and scales with one to a few enlarged ctenii. L. waitei [L. robustus Fourmanoir and L. addisi (Smith) are synonyms] usually has 19 or 20 pectoral rays and 51-59 lateral-line scales. L. whitleyi has modally 21 pectoral rays and 65-74 lateral-line scales. L. taeniatus, described from 4 specimens from the Banda Sea, Indonesia, has 19 pectoral rays, 56-60 lateral-line scales, and a pattern of narrow pale yellow and orange stripes on the body, shading to a broad magenta zone posteriorly. L. williamsi, described from 4 specimens from the Loyalty Islands, is similar to L. microlepis in having enlarged ctenii on many scales, II,9 anal rays, and high counts of lateral-line scales and pectoral rays; it differs in its more elongate body, longer head, shorter snout, and a color pattern in alcohol consisting of a narrow pale stripe within the dusky area of the back.