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Metanephrops japonicus

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Taxonomy [top]

Kingdom Phylum Class Order Family
ANIMALIA ARTHROPODA MALACOSTRACA DECAPODA NEPHROPIDAE

Scientific Name: Metanephrops japonicus
Species Authority: (Tapparone-Canefri, 1873)
Common Name(s):
English Japanese Lobster
Synonym(s):
Nephrops japonicus Tapparone-Canefri, 1873

Assessment Information [top]

Red List Category & Criteria: Data Deficient ver 3.1
Year Published: 2013
Date Assessed: 2009-12-03
Assessor(s): Butler, M., Chan, T.Y., Cockcroft, A., MacDiarmid, A. & Wahle, R.
Reviewer(s): Collen, B., Livingstone, S. & Richman, N.
Contributor(s): Batchelor, A., De Silva, R., Dyer, E., Kasthala, G., Lutz, M.L., McGuinness, S., Milligan, H.T., Soulsby, A.-M. & Whitton, F.
Justification:
Metanephrops japonicus has been assessed as Data Deficient. Further information on the impact of commercial exploitation on its population size and trends is required. This species is harvested throughout much of its range. Despite anecdotal and observational evidence from fishermen about population declines, there is a lack of quantitative data from which to quantify rates of decline. Further research is recommended to determine the abundance of this species and the impact of trawling before a more accurate assessment of conservation status can be made.

Geographic Range [top]

Range Description: This species occurs off the Pacific coast of Japan: from Choshi, Honshu to the east coast of Kyushu (Holthuis 1991).
Countries:
Native:
Japan (Honshu, Kyushu, Shikoku)
FAO Marine Fishing Areas:
Native:
Pacific – northwest
Range Map: Click here to open the map viewer and explore range.

Population [top]

Population: There is no population information for this species.
Population Trend: Unknown

Habitat and Ecology [top]

Habitat and Ecology: This species is found in mud substrate at depths of 200-440 m, preferring 200-300 m (Holthuis 1991).
Systems: Marine

Use and Trade [top]

Use and Trade: This species is fished using pots and by commercial trawlers throughout its range (Holthuis 1991). It is sold both fresh and frozen, and is a highly-prized gourmet species. It is mainly fished in Chiba, Suruga Bay, the Boso Peninsula, and Sagami Bay during the cold seasons (Chan and Yu 1991, Okamoto 2008).

Threats [top]

Major Threat(s): The stock of Sagami Bay appears not to be large, and is threatened by high fishing pressure. So far this has not caused a significant change in the size distribution of the catch, although this may be due to the aggregating nature of this species into size groups (Chan and Yu 1991). Over-fishing has resulted in decreased numbers. Rearing of juveniles in captivity has been successful (Okamoto 2008). However the lack of catch per unit effort data makes it difficult to interpret these observations.

Conservation Actions [top]

Conservation Actions: There are no species-specific conservation measures in place for this species. Studies have investigated captive rearing of this species with some success (Okamoto 2005, 2008). This is part of a project initiated to develop land-based aquaculture in order to restock overfished areas (e.g., Suruga Bay); something which has not been achieved with any nephropid lobster (Okamoto 2008).
Further work is needed to determine the impact of trawling on populations, especially those which might be affected by high fishing pressure. If there is evidence that populations are being severely impacted further measures may need to be introduced (if not already in place) to limit the size and/or timing of catches. These include: license limitation; vessel restrictions; seasonal closures or periods of no fishing and minumum size limits. Although Chan and Yu (1991) reported no change in size distribution in harvested populations.

Citation: Butler, M., Chan, T.Y., Cockcroft, A., MacDiarmid, A. & Wahle, R. 2013. Metanephrops japonicus. The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>. Downloaded on 25 October 2014.
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