Hydrolagus

Soto, Jules M. R. & Vooren, Carolus M., 2004, Hydrolagus matallanasi sp. nov. (Holocephali, Chimaeridae) a new species of rabbitfish from southern Brazil, Zootaxa 687, pp. 1-10 : 8

Key to the western Atlantic Hydrolagus species

[Modified from Bigelow and Schroeder (1953) and Didier (2004)]

1a. Upper margin of second dorsal fin straight..................................................... H. alberti

1b. Upper margin of second dorsal fin notably concave at middle region of second dorsal fin base .......................................................................................................................... 2

2a. 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

2b. 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