|Scientific Name:||Hydrolagus barbouri|
|Species Authority:||(Garman, 1908)|
|Red List Category & Criteria:||Data Deficient ver 3.1|
|Reviewer(s):||Nakaya,K., Sato, K., Kyne, P.M., Fowler, S.L. & Compagno, L.J.V. (Shark Red List Authority)|
Hydrolagus barbouri is a regional endemic known only from the Northwest Pacific off northern Japan at depths of 250 to 1,100 m. Little is known of the biology of this species, but it appears to be relatively common in research trawls and may be abundant in the area. Reproduction studies indicate that this species appears to produce eggs all year round with no detectable spawning season. Populations appear to be partly segregated. Not known to be targeted, but may be utilized when caught as bycatch in trawl fisheries and by subsistence fishers in the region. Probably not often caught as this species is most abundant in the deeper part of its range and may be at, or beyond the usual depths of the local trawl fishery. Potentially threatened as bycatch and possibly as a target species if local commercial trawl fishing effort increases in this region in the future, particularly due its restricted geographic range.
|Range Description:||Known only from the eastern coast of Japan from Hokkaido to Tokyo. This species appears to be a regional endemic, most abundant in the northern and southern areas off Tohoku.|
|FAO Marine Fishing Areas:||
Pacific – northwest
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Very little is known of population size and structure although the species appears to be somewhat abundant with captures including a wide range of juveniles and adults.|
|Current Population Trend:||Unknown|
|Habitat and Ecology:||Deepwater edge of shelf and upper slope dweller reported from depths of 250 to 1,100 m, but seems to be most common at 600 to 800 m. Size range 18 to 86 cm TL; 8 to 48 cm body length (BDL).
Oviparous. A recent study of the distribution and reproductive biology indicates that this species appears to produce eggs all year round with no detectable spawning season. Populations appear to be partly segregated (Kokohu et al. 2003).
Life history parameters
Age at maturity (years): Unknown.
Size at maturity (precaudal length): Female: 55 cm PCL; Male: 48 cm PCL.
Longevity (years): Unknown.
Maximum size (total/body length): 86 cm TL; 48 cm BDL.
Size at birth: ~18 cm TL; 8 cm BDL.
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.
|Major Threat(s):||Known to occur in fair numbers in deepwater research trawls. Not known to be targeted, but may be utilized when caught as bycatch in trawl fisheries, although probably not often caught as this species is most abundant in the deeper part of its range and may be at, or beyond the usual depths of the local trawl fishery. Potentially threatened as bycatch and possibly as a target species if local commercial trawl fishing effort increases in this region in the future.|
No management or conservation measures known to be in place.
The effective implementation of a national management plan (under the FAO International Plan of Action for the Conservation and Management of Sharks: IPOA-Sharks) will help to facilitate the conservation and management of all chondrichthyan species in the country. Japan's National Plan Of Action was available in 2001.
|Citation:||Dagit, D.D. 2006. Hydrolagus barbouri. The IUCN Red List of Threatened Species 2006: e.T60190A12307046. http://dx.doi.org/10.2305/IUCN.UK.2006.RLTS.T60190A12307046.en . Downloaded on 04 October 2015.|
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