[Modified from Bigelow and Schroeder (1953) and Didier (2004)]
1 a. Upper margin of second dorsal fin straight..................................................... H. alberti
1 b. Upper margin of second dorsal fin notably concave at middle region of second dorsal fin base.......................................................................................................................... 2
2 a. Body pale brown, without reticulations and spots; ventral base of pectoral fin darkish brown; eye length nearly equal to preorbital length; dorsal spine length 4 / 5 of head length; pelvic claspers in males divided for nearly 1 / 2 their length............ H. mirabilis
2 b. Brown coloration with reticulations and spots covering dorsoventrally the body; ventral base of pectoral fin whitish; eye length about 2 / 3 of preorbital length; dorsal spine