Chimaeras are cartilaginous fish in the order Chimaeriformes. They are related to the sharks and rays, and are sometimes called ghost sharks, ratfish (not to be confused with the "rattails"), or rabbitfishes.
Chimaeras live in temperate ocean floors and grow up to two meters long. Like other members of the class Chondrichthyes, chimaeras have a skeleton constructed of cartilage. Their skin is smooth and lacks scales, and their color can range from black to brownish gray.
For defense, most chimaeras have a venomous spine located in front of the dorsal fin.
Chimaeras resemble sharks in some ways: they employ claspers for internal fertilization of females and they lay eggs with leathery cases. They differ from sharks in that their upper jaws are fused with their skulls; they have separate anal and urogenital openings; and they lack the many sharp and replaceable teeth of sharks, having instead a few large permanent grinding tooth plates.
Albino Puget Sound ratfish
A rare albino Puget Sound ratfish was discovered near Whidbey Island, Washington. It is the only pure albino among the 7.2 million specimens in the University of Washington's fish collection.
In some classifications the chimaeras are included (as subclass Holocephali) in the class Chondrichthyes of cartilaginous fishes; in other systems this distinction may be raised to the level of class. Chimaeras also have some characteristics of bony fishes.
There are about forty species in six genera and three families:
- Genus Chimaera
- Genus Hydrolagus
- Smalleyed rabbitfish, Hydrolagus affinis (de Brito Capello, 1868)
- African chimaera, Hydrolagus africanus (Gilchrist, 1922)
- Hydrolagus alberti Bigelow & Schroeder, 1951
- Hydrolagus alphus Quaranta et al., 2006.
- Hydrolagus barbouri (Garman, 1908)
- Pale ghost shark, Hydrolagus bemisi Didier, 2002
- Spotted ratfish, Hydrolagus colliei (Lay & Bennett, 1839)
- Philippine chimaera, Hydrolagus deani (Smith & Radcliffe, 1912)
- Hydrolagus eidolon (Jordan & Hubbs, 1925)
- Hydrolagus homonycteris Black Ghost Shark
- Blackfin ghostshark, Hydrolagus lemures (Whitley, 1939)
- Hydrolagus macrophthalmus de Buen, 1959
- Hydrolagus marmoratus Marbled Ghost Shark
- Hydrolagus matallanasi Sotto & Vooren, 2004
- Hydrolagus mccoskeri
- Hydrolagus media (Garman, 1911).
- Large-eyed rabbitfish, Hydrolagus mirabilis (Collett, 1904)
- Spookfish, Hydrolagus mitsukurii (Jordan & Snyder, 1904).
- Dark ghost shark, Hydrolagus novaezealandiae (Fowler, 1911)
- Hydrolagus ogilbyi (Waite, 1898)
- Hydrolagus pallidus Hardy & Stehmann, 1990
- Purple chimaera, Hydrolagus purpurescens (Gilbert, 1905)
- Pointy-nosed blue chimaera, Hydrolagus trolli Didier & Séret, 2002
- Hydrolagus waitei Fowler, 1908
- Hydrolagus sp. D/G Giant Black Chimaera
- Hydrolagus sp. F Peruvian Ratfish