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Hydrolagus alphus 

Scope: Global
Language: English
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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Chondrichthyes Chimaeriformes Chimaeridae

Scientific Name: Hydrolagus alphus Quaranta, Didier, Long & Ebert, 2006
Common Name(s):
English Whitespot Ghost Shark

Assessment Information [top]

Red List Category & Criteria: Data Deficient ver 3.1
Year Published: 2009
Date Assessed: 2008-12-01
Assessor(s): Kyne, P.M. & Valenti, S.V.
Reviewer(s): Quaranta, K.L., Ebert, D.A. & Gibson, C. (Shark Red List Authority)
Justification:
The Whitespot Ghostshark (Hydrolagus alphus) is a recently (2006) described and poorly known deepwater chimaeroid, likely endemic to the Galapagos Islands in the Southeast Pacific. Known only from two captured and two observed specimens from the rocky steep slope around the archipelago at depths of 630–907 m. Largest captured specimen was a 48.0 cm TL (24.4 cm body length) sub-adult female. Fishing activities around the Galapagos archipelago are mostly limited to the coastal zone (pelagic longlining also occurs). The habitat of this species is unsuitable for trawling, and demersal deepwater fisheries are not presently operating within its range. However, the overall lack of information available on the species, stemming from limited specimens and records, precludes an assessment beyond Data Deficient at this time.

Geographic Range [top]

Range Description:Species documented from four scattered locations around the Galapagos Islands in the Southeast Pacific as per the original species description (Quaranta et al. 2006). See Quaranta et al. (2006) for exact collection details.

Quaranta et al. (2006) notes that given the high degree of endemism of fishes around the Galapagos Archipelago, H. alphus is likely to be endemic to the islands.
Countries occurrence:
Native:
Ecuador (Galápagos)
FAO Marine Fishing Areas:
Native:
Pacific – southeast
Additional data:
Lower depth limit (metres):907
Upper depth limit (metres):630
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:This recently described species is known only from two specimens and an additional two observations, from four locations as recorded in the original species description (Quaranta et al. 2006).
Current Population Trend:Unknown
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:All known specimens of the species were collected or observed at depths ranging from 630–907 m, within 3 m of the bottom (Quaranta et al. 2006). Quaranta et al. (2006) reported habitat adjacent to capture sites as ‘slopes and ledges containing large volcanic boulders, cobbles, and gravels, frequently overlain by, or interspersed with, patches of sand and coarse silt’. Two measured specimens were an adult male of 41.9 cm TL and 24.9 cm body length (BDL), and a sub-adult female of 48.0 cm TL and 24.4 cm BDL (Quaranta et al. 2006).
Systems:Marine

Threats [top]

Major Threat(s): Fishing activities around the Galápagos archipelago are mostly limited to the coastal zone, although pelagic longlining also occurs. The habitat of this species (steep rocky volcanic slopes and ledges) is unsuitable for trawling, and demersal deepwater fisheries are not presently operating within its range.

Conservation Actions [top]

Conservation Actions: The Galápagos archipelago is covered by the 133,000 km² Galápagos Marine Reserve which includes strictly protected areas and prohibits industrial fishing but allows artisanal fishing (Wood 2007). However, both the enforcement of regulations and the prosecution of illegal fishers are often lacking.

The species was discovered during surveys using manned submersibles, as its habitat is unsuitable for more traditional sampling methods (i.e., trawling) (Quaranta et al. 2006). Further sampling would assist in better defining the distribution and occurrence of the species, which given the isolation of the Galápagos Islands and the associated high level of endemism, is likely endemic to the archipelago (Quaranta et al. 2006).

Citation: Kyne, P.M. & Valenti, S.V. 2009. Hydrolagus alphus. The IUCN Red List of Threatened Species 2009: e.T161324A5398233. . Downloaded on 15 October 2018.
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