This species is distinguished from its congeners H. fulminantis and H. shibattai by the following characters: in males, pectoral fin red (vs. hyaline), the filamentous rays well-developed on the tips of the dorsal and anal fins in adults (vs. absent or rudimentary, poorly visible), and the second proximal radial of the dorsal fin between the neural spines of the 8th and 9th vertebrae (vs. between neural spines of 6th and 7th vertebrae); differs from H. shibattai by having the dorsal-fin origin posterior to the anal-fin origin in males (vs. anterior), the distinctive red bars restricted to the anterior portion of the flank males (vs. extending over the whole flank), and absence of contact organs on the pectoral fin in males (vs. present) (Ref. 119423).