Idiastion
| Idiastion | |
|---|---|
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Scorpaeniformes |
| Family: | Scorpaenidae |
| Tribe: | Scorpaenini |
| Genus: | Idiastion Eschmeyer, 1965 |
| Type species | |
| Idiastion kyphos Eschmeyer, 1965[1]
| |
Idiastion is a small genus of marine ray-finned fish belonging to the family Scorpaenidae, the scorpionfishes. They are found in the Atlantic and Pacific oceans.
Taxonomy[edit]
Idiastion was first described as a genus by the American ichthyologist William N. Eschmeyer in 1965 when he was describing its type species, Idiastion kyphos, from the southeastern Caribbean Sea, between Venezuela and Grenada.[2] Subsequently two more species have been added to the genus from the Pacific Ocean.[3] The genus is classified within the tribe Scorpaenini in the subfamily Scorpaeninae of the scorpionfish family Scorpaenidae.[4] The genus name Idiastion is the Greek word meaning "hermit" or "recluse", alluding to the rarity of the scorpionfishes at the depths at which Idiastion was collected from.[5]
Species[edit]
There are currently three recognized species in this genus:[3]
- Idiastion hageyi McCosker, 2008(Galapagos humpback scorpionfish)
- Idiastion kyphos Eschmeyer, 1965 (Sharpcheek scorpionfish)
- Idiastion pacificum Ishida & Amaoka, 1992 (Flame humpback scorpionfish)
Characteristics[edit]
Idiastion scorpionfishes have a deep body, deepest behind the head with a hump backed shape. They have well developed, robust spines which can have more than one point. They do not have an occipital pit behind their large eyes which have a suborbital ridge armed with between 5 and 8 spines. There are 4 spines on the preoperculum with the uppermost one being the longest and being located some distance from the other 3 spines. They have small, simple teeth on the jaws and the roof of the mouth. They have 12 spines and 9 soft rays in the dorsal fin and 3 spines and 5 soft rays in the anal fin. The pectoral fin has 17-19 rays, the central rays being the longest and the uppermist ray and bottom 7-9 rays are unbranched with the lower ones being fleshy with their tips protruding beyond the membrane. They have a complete lateral line with tubes on the scales and a small swim bladder.[6] These scorpionfishes are small fishes with standard lengths ranging from 5.3 cm (2.1 in) in I. kyphos and 12.3 cm (4.8 in) in I. pacificum.[3]
Distribution and habitat[edit]
Idiastion scorpionfishes are found in the western Atlantic Ocean (I. kyphos), the Galápagos Islands (I. hageyi) and around Japan and over the Emperor Seamounts in the northwestern Pacific (I. pacificum).[3][7] They live close to the bottom over reefs and soft substrates.[6]
References[edit]
- ^ Eschmeyer, William N.; Fricke, Ron & van der Laan, Richard (eds.). "Genera in the family Scorpaenidae". Catalog of Fishes. California Academy of Sciences. Retrieved 9 January 2022.
- ^ Eschmeyer, William N.; Fricke, Ron & van der Laan, Richard (eds.). "Species in the genus Idiastion". Catalog of Fishes. California Academy of Sciences. Retrieved 9 January 2022.
- ^ a b c d Froese, Rainer and Pauly, Daniel, eds. (2012). Species of Idiastion in FishBase. December 2012 version.
- ^ J. S. Nelson; T. C. Grande; M. V. H. Wilson (2016). Fishes of the World (5th ed.). Wiley. pp. 468–475. ISBN 978-1-118-34233-6.
- ^ Christopher Scharpf & Kenneth J. Lazara, eds. (2 October 2021). "Order Perciformes (Part 9): Suborder Scorpaenoidei: Family Scorpaenidae". The ETYFish Project Fish Name Etymology Database. Christopher Scharpf and Kenneth J. Lazara. Retrieved 9 January 2022.
- ^ a b "Genus: Idiastion, Scorpionfish". Shorefishes of the Greater Caribbean online information system. Smithsonian Tropical Research Institute. Retrieved 9 January 2021.
- ^ Makoto Okamoto; Hiroyuki Motomura; Koichi Hoshino; Takashi Yanagimoto; and Toshiro Saruwatari. "Occurrence and Additional Specimens of a Scorpionfish, Idiastion pacificum (Actinopterygii: Scorpaeniformes:Scorpaenidae), from the Central North Pacific" (PDF). Species Diversity. 17: 1–5.