Handfish are any angler fish within the family Brachionichthyidae, one of the world’s most endangered marine fish. Brachionichthyidae family is a group which comprises five genera and 14 extant species. They are found in the coastal waters of Southern Australia and Tasmania. These benthic marine fish are unusual in the way they propel themselves by walking on the sea floor rather than swimming and lives on a depth of 6.5 to 98 feet.
The handfish is unusual in that it has highly adapted pectoral fins, which appear like hands (hence the name) and allow it to walk on the sea floor. Handfishes are small (up to 120 mm in length), slow-moving, benthic fishes grow up to 15 cm long, and have skin covered with denticles (tooth-like scales), giving them the alternate name warty anglers.
Like other anglerfish, they possess an illicium, a modified dorsal fin ray above the mouth, but it is short and does not appear to be used as a fishing lure. The second dorsal spine is joined to the third by a flap of skin, making a crest.
To swim they use anal and tail fins to propel themselves in the water. Females are believed to reach sexual maturity after two to three years at lengths of 75–80 mm. Males perform courtship ritual to attract females. They spawn during September and October. Females lay a number of eggs varying from 80 to 250 eggs on a variety of vertical objects, including sea grasses, sponges, macrophytic algae, polychaete worm tubes, and stalked ascidians.
They feed by sucking in prey items, including shrimps, small fish and small crustaceans such as amphipods. Exact lifespan of spotted handfish is unknown. The most urgent matter concerning the survival of the species is to address the nuisance threat posed by the presence of an introduced species of starfish (Asterias amurensis), which prey on the fish eggs.