Helicolenus
Helicolenus is a genus of marine ray-finned fishes belonging to the family Scorpaenidae where they are classified within the subfamily Sebastinae, the rockfishes. The species in this genus are found in the Indian, Atlantic and Pacific oceans. Taxonomy. "Helicolenus" was described by a genus in 1896 by the American ichthyologists George Brown Goode & Tarleton Hoffman Bean using "Scorpaena dactyloptera" as its type species which had originally been described by the Genevan physician, naturalist, chemist, botanist and ichthyologist François Étienne Delaroche in 1809. The genus name is a compound of "helikos" which means "twisted" or "curved" but meaning "strong  according to Goode and Bean, possibly in error for hadros"; and "oleni" meaning "elbow" or "arm", an allusion to the “strong pectoral fins” of "H. dactylopterus". Species. There are 9 recognised species: Characteristics. "Helicolenus" fishes have a large head which bears spiny ridges and has a large mouth. There are 5 spines on the posterior and lower margin of the preoperculum and two obvious spines close to the posterior of the operculum. Their dorsal fins have 11-13 robust spines and 10 to 14 soft rays. Species in this genius vary in length from a standard length of in "H.  fedorovi" and "H. hilgendorfii" up to a total length of in "H. dactylopterus". Distribution and habitat. "Helicolenus" rockfishes are found in the Pacific and Atlantic oceans. They are benthic, demersal and bathydemersal fishes. Biology. "Helicolenus" rockfishes are ovoviviparous and fertilisation is internal. They are predators of cephalopods, echinoderms, crustaceans and fishes. They have been known to live for up to 42 years. Fisheries. "Helicolenus" rockfishes are commercially important species in fisheries in some regions such as southern Australia.