Brachionichthys Bleeker, 1855: 12, 21. Type species: Lophius hirsutus Lacepède, 1804, by subsequent designation of Gill, 1878: 222.

Definition. Members of the genus Brachionichthys are unique among brachionichthyids in having the following combination of features: body relatively elongate (depth 28–35% SL at second dorsal-fin origin), head weakly compressed, oval in cross section, relatively small, length 45–49% SL; mouth relatively small, caudal peduncle long, 7–11% SL; illicium very slender, 4–12 times length of esca; skin surface rough, densely covered with monospinulate scales; spinules upright, protruding well above skin surface, originating from centre of scale base; scale bases subcircular, not deeply embedded; dermal appendages present on arm of pectoral-fin (sometimes present on ventrolateral surface of body); no enlarged fleshy warts on skin; black spots and/or streaks over body, and dorsal and caudal fins; pectoral-fin usually with 7 rays; anal-fin rays 8–11 (mainly 9–10); vertebrae 22–26.

Species. Presently includes two valid species, Brachionichthys australis Last, Gledhill & Holmes, 2007 and B. hirsutus (Lacepède, 1804).

Remarks. Diagnoses of the included taxa (i.e. Brachionichthys australis and B. hirsutus) by Last et al. (2007) were constructed to distinguish these species from the few other nominal brachionichthyids documented at the time, as well as incorporating characters useful for distinguishing undescribed specieslevel taxa then provisionally considered referable to the genus Brachionichthys. Further research has confirmed that these new taxa need to be assigned to new genera erected in this paper. Hence, species diagnoses have been modified herein to include characters useful in distinguishing each of these species.

Members of the genus Brachionichthys are distinguishable from all other handfishes in having a relatively elongate body, a colour pattern of dark streaks and/or spots, and rough skin that is densely covered with monospinulate scales. The scales have upright spinules that protrude well above the skin surface and originate centrally from their bases. Pezichthys has spiny scales with spinules originating centrally but their spinules are bifid; other genera are smooth and naked, warty or have monospinulate or bicuspid scales with oblique spinules originating at the posterior margin of the scale base.

Pectoral-fin ray counts are reasonably stable in this group but aberrations can occur. The typical count for Brachionichthys is 7 rays (based on 114 specimens with both left and right pectoral counted). However, two specimens of B. hirsutus, CSIRO T 1989 –01 (one of three individuals) and CSIRO H 2629–04 (one of 7 individuals), had 6 and 8 rays respectively on one side of the body (the other side had a typical count of 7 rays). Pezichthys (5 species) also has 7 pectoral-fin rays, and some species of Sympterichthys (2 species) and Thymichthys (2 species) also can have 7 rays.

Additional material has been examined since Last et al. (2007) which has extended geographic ranges and shed light on possible regional extinctions of species.