|Scientific Name:||Hydrolagus colliei|
|Species Authority:||(Lay & Bennett, 1839)|
Chimaera media Garman, 1911
|Taxonomic Notes:||Synonym = Chimaera media Garman, 1911 (Didier and Rosenberger 2002).
Fowler (1910) stated that Chimaera neglecta Ogilby, 1888 is probably a synonym of H. colliei, but it is more likely a synonym of H. novaezealandiae (Didier and Rosenberger 2002).
|Red List Category & Criteria:||Least Concern ver 3.1|
|Reviewer(s):||Ebert, D.A., Kyne, P.M., Fowler, S.L. & Compagno, L.J.V. (Shark Red List Authority)|
A common species found in nearshore waters to depths of 913 m along the west coast of North America from Southwestern Alaska to Baja California, Mexico (including the Gulf of California). This species appears to be abundant throughout most of its range, although not common in Alaskan waters. One of the best studied of all chimaeroid fishes, life history studies indicate segregation of populations by size and sex and seasonal abundance in parts of its range. Limited information on reproduction indicates that eggs are laid in pairs every 10 to 14 days over a period of several months with development taking up to 12 months. Available fisheries data from the Northeast Pacific indicates this species comprises a large proportion of the vertebrate biomass in Puget Sound (Quinnell and Schmitt 1991), although reported catches from California, Oregon and Washington are very small. This ratfish is not a targeted species and appears to be collected and utilized only locally in the Northeast Pacific and is taken as a bycatch in commercial trawl fisheries. This species is rarely landed from the Gulf of California where it appears to inhabit waters at depths greater than 180 m. Evidence does not suggest that the small local fishery and/or bycatch are impacting the population in the Gulf of California. Given its wide distribution, depth range, abundance in some areas and evidence to suggest that the impact of fisheries is minimal, the species is assessed as Least Concern.
|Range Description:||Widespread off the western coast of North America from Southwestern Alaska to Baja and the Gulf of California, being most abundant between British Columbia, Canada and southern California, USA.|
Native:Canada (British Columbia); Mexico (Baja California); United States (Alaska, California, Oregon, Washington)
|FAO Marine Fishing Areas:||
Pacific – eastern central; Pacific – northeast
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Very little is known about their movement patterns other than they seem to be seasonally abundant in some areas. Populations appear to segregate by sex and size with larger fish moving into shallower waters while juveniles aggregate in deeper waters (Mathews 1975, Quinn et al. 1980).|
|Habitat and Ecology:||
Prefers muddy, soft bottoms. One of the few chimaeroids that occurs in nearshore waters and has been observed at the surface, but generally occurs at depths of 100 to 913 m. The species also occurs into the intertidal zone in the northern parts of its range. In southern California it has been reported as common on some reef slopes, particularly off Malibu and Redondo Beach below depths of 30 m. In the Gulf of California they are rare in water less than 183 m deep. Prefers water temperatures of 45 to 48°F (Ebert 2003).
Oviparous with peak spawning seasons in the spring and fall. Eggs are laid in pairs every 10 to 14 days over a period of several months. The incubation period within the eggcase is about 12 months, with newborns emerging at about 14 cm TL (Didier and Rosenberger 2002). The spine is known to be venomous in this species (Halstead and Bunker 1952). Johnson and Horton (1972) reported that attempts at age determination based on length-frequency distributions were inconclusive and that the use of hard body parts for ageing was unsuccessful. Diet consists of a wide range of bottom dwelling invertebrates and fishes. They are known to be cannibalistic, feeding on both free-swimming individuals and on their own eggcases (Johnson and Horton 1972).
Life history parameters
Age at maturity (years): Unknown.
Size at maturity (body length): Female: 24 to 25 cm BDL; Male: 18.5-20.0 cm BDL.
Longevity (years): Unknown.
Maximum size (total/body length): 60 cm TL; 36 cm BDL.
Size at birth: 14 cm TL.
Average reproductive age (years): Unknown.
Gestation time (months): Unknown.
Reproductive periodicity: Unknown.
Average annual fecundity or litter size: Unknown.
Annual rate of population increase: Unknown.
Natural mortality: Unknown.
Potentially threatened by inshore commercial trawling activities. A fishery for this species has been suggested, but has never proven commercially viable; however, there is the potential this "trash" species may become targeted as other more valuable species are depleted.
Available fishery data from the Northeast Pacific indicates this species comprises a large proportion of the vertebrate biomass in Puget Sound (Quinnell and Schmitt 1991), although reported catches from California, Oregon and Washington are very small. For example, State of Washington Department of Fisheries reported only 8 round pounds for 1992-1993 (Keith Wolf, pers. comm.) and Oregon landings in 1992 and 1993 were 250 pounds and 98 pounds, respectively (John Griffith, pers. comm.). This species is not a targeted species and appears to be collected and utilized only locally in the Northeast Pacific and is taken as a bycatch in commercial trawl fisheries. This species is rarely landed from the Gulf of California and appears to inhabit waters at depths greater than 180 m. Evidence does not suggest that the small local fishery and/or bycatch are impacting the population in the Gulf of California.
No management or conservation measures are currently known to be in place, except in Oregon where trawlers utilize gear to avoid ratfish and other unwanted bycatch. This species is generally avoided as much as possible as the spiny frontal tenaculum and dorsal spine tangles in nets.
The development and implementation of management plans (national and/or regional e.g., under the FAO International Plan of Action for the Conservation and Management of Sharks: IPOA-Sharks) are required to facilitate the conservation and management of all chondrichthyan species in the region.
|Citation:||Dagit, D.D. 2006. Hydrolagus colliei. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 28 July 2015.|