Key to species of the genus Minous [modified from Eschmeyer et al. (1979) with data from Amaoka & Kanayama (1981), Mandrytsa (1990, 1993) and this study] 1a. First dorsal-fin spine subequal to or longer than second spine, well separated from second spine base................... 2 1b. First dorsal-fin spine much shorter than second spine (usually less than half length, sometimes extremely small), close to second spine base........................................................................................ 6 2a. Posterior lacrimal spine relatively short, not bayonet-shaped (Eschmeyer et al. 1979: fig. 2a; Fig. 2A); caudal fin without transverse dark bands; pectoral fin inner surface with dark brown stripes along rays (Fig. 4B)............................................ M. quincarinatus (western Pacific Ocean: Japan, Taiwan, Philippines and northern Australia) (Figs. 3C, 4B) 2b. Posterior lacrimal spine longer than anterior spine, bayonet-shaped (Eschmeyer et al. 1979: fig. 2b; Fig. 2B); caudal fin with transverse dark band(s) (Fig. 3A, D–F); pectoral fin inner surface generally without distinct markings along rays (Figs. 4A, C– E).................................................................................................. 3 3a. Dorsal-fin rays IV, 18 or 19 (Table 1)..................... M. andriashevi (off Seychelles and Somalia) (Figs. 3A–B, 4A) 3b. Dorsal-fin rays VIII–XI, 9–14............................................................................ 4 4a. Body with numerous dark spots ventrally, oblique alternating dark and light stripes dorsally (Fig. 3D)....................................................................................... M. usachevi (Gulf of Aden) (Figs. 3D, 4C) 4b. Body without dark spots (Fig. 3D, E)...................................................................... 5 5a. Dorsal-fin spines usually 9 (Table 1); caudal fin usually with 3 or 4 transverse wavy bands; soft-rayed portion of dorsal fin with wavy bands (Fig. 3E); pectoral fin inner surface with irregular light blotches on dark background (preserved specimens) (Fig. 4D)............................................................. M. versicolor (Australia) (Figs. 3E, 4D)

Published as part of Matsunuma, Mizuki & Motomura, Hiroyuki, 2018, Three new species of the Indo-Pacific stingfish genus Minous (Synanceiidae: Minoinae) with redescriptions of M. trachycephalus (Bleeker 1855) and M. pictus Günther 1880, pp. 201-257 in Zootaxa 4455 (2) on page 204, DOI: 10.11646/zootaxa.4455.2.1, http://zenodo.org/record/1457101