|Scientific Name:||Galeus atlanticus|
|Species Authority:||(Vaillant, 1888)|
Pristiurus atlanticus Vaillant, 1888
|Taxonomic Notes:||Galeus atlanticus was originally described by Vaillant (1888) from a specimen caught off Cape Spartel (Atlantic NW coast of Morocco) but has since then been often confused with the very similar sympatric species, Galeus melastomus. The name was resurrected by Munoz-Chapuli and Perez-Ortega (1985). The two species are highly similar externally, but for Rey et al. (in press) a slightly different patch pattern allows the separation of the individuals of the two species. A genetic study conducted in the Algarve showed that this is indeed a separate species from G. melastomus (Freitas 2004, Castilho et al. submitted).|
|Red List Category & Criteria:||Near Threatened ver 3.1|
|Assessor(s):||Coelho, R., Rey, J., Serena, F. & Mancusi, C.|
|Reviewer(s):||Séret, B., Cavanagh, R.D. & Valenti, S.V. (Shark Red List Authority)|
A little known demersal catshark reported at depths of 330 to 710 m. This shark has a narrow extent of occurrence (approximately 50,000 km2), being recorded only in the Mediterranean, from the Straight of Gibraltar to Cape Gata, in Northeast Atlantic from Cape S. Vicente to the Straight of Gibraltar. Off West Africa this species is only confirmed from the type specimen captured off Cape Spartel (northwest coast of Morocco), and from one specimen caught off Mauritania (Castilho et al. submitted), and other reports from this region require confirmation. Previously synonymised with Galeus melastomus, this is now a valid species with both morphometric, external field marks and genetic evidence to show this. Nonetheless, given the very close resemblance with other species, this species is still probably being confused with G. melastomus and G. polli, at this time. The entire narrow depth and geographic range of this species is currently being exploited by deepwater fisheries that take it as bycatch. Although the species is usually discarded, nothing is known of the mortality of these discards. Larger individuals are marketed with G. melastomus. Given that the entire narrow range of this species is heavily fished, and that fishing pressure is unlikely to decrease in the future, the species is given a precautionary assessment of Near Threatened, due to concern that it may meet Vulnerable A3d. If the range of this species proves to extend further along the African coasts, then it may be afforded more protection, especially if part of the population occurs in areas outside the range of fisheries and the assessment would then need to be revisited.
|Range Description:||This species has a very narrow distribution range in all the areas in which it occurs. Some identification problems and possible confusion with G. melastomus and G. polli might mean that the distribution of this species may be larger but unknown at this point.
This species is presently calculated to have a total extent of occurrence of around 50,000 km2, from which 25,000 km2 are in the Northeast Atlantic and 25,000 km2 are in the Mediterranean Sea. It is only known from one specimen off west Africa at this time, so the area of occupancy in this region might be very restricted.
In the Northeast Atlantic this species is known from the Gibraltar Strait (J. Rey pers. comm.) to the Vicente Cape (Southwest coast of Portugal) (R. Coelho pers. comm.), where it is captured regularly. In this area, most of the records are adult specimens.
In the Mediterranean it is known only in its western part, in Spanish waters, from Gibraltar Strait to Cape Gata, being especially abundant in the Alboran Sea and becoming gradually less abundant towards the East to the longitude of Cape Gata (Rey et al. in press). High numbers of juveniles have only been reported from the Alboran Sea (J. Rey pers. comm. 2006).
Off West Africa this species is only confirmed from the type specimen captured off Cape Spartel (northwest coast of Morocco) and from one specimen capture off Mauritania (Castilho et al. submitted). There are unconfirmed reports of this species being captured off the coast of Morocco (F. Litvinov pers. comm. 2006).
Native:Mauritania; Morocco; Portugal; Spain
|FAO Marine Fishing Areas:||
Atlantic – eastern central; Atlantic – northeast; Mediterranean and Black Sea
|Range Map:||Click here to open the map viewer and explore range.|
Off the Southern Portuguese coast, this species has been regularly captured since 2003 (when it started to be separated from G. melastomus) by deep water commercial longliners, targeting wreck fish, Polyprion americanus and conger eels, Conger conger. Samplings aboard these commercial boats have shown that the species is captured in a fairly narrow depth range (470 to 580 m) with a CPUE of 1.83 specimens/1,000 hooks (s.d.=1.18) (Coelho unpublished data).
The MEDITS trawl survey covers the north Mediterranean coast almost continuously from western Morocco and Spain in the west Mediterranean to the Aegean Sea in the eastern Mediterranean. Six trawl surveys were carried out in the coastal areas of four arbitrary geographically defined areas: Western (Morocco, Spain, France), Western Central (Tyrrhenian, Corsican, Sardinia and Sicily coasts), Eastern Central (Adriatic, Ionian and Albanian coasts) and the Eastern (Aegean Sea). A total of 6,336 tows were performed between 1994 and 1999 in depths ranging from 10 to 800 m. Analysis of MEDITS data between 1994 and 1999 show a very low frequency of occurrence of G. atlanticus. Out of the total number of hauls in the Mediterranean this species was captured in only one (0.01%) in the Western area (Baino et al. 2001). However, it is likely that this species was still being confused for G. melastomus at this time.
The Spanish Medits surveys that have annually covered the Spanish waters of the Mediterranean since 1994, up to depths of 800 m, have shown that this species only occurs in the western end of the Mediterranean, from the Straight of Gibraltar to Cape Gata, being abundant only in the Alboran Sea (western part of this range of occurrence) and decreasing gradually in abundance until off Cape Gata longitude (Rey et al. 2005).
Presently this species in confirmed in this area only from the holotype specimen that was captured off cape Spartel (northwest Morocco) (Vaillant 1888) and from the specimen caught off Mauritania (Castilho et al. submitted). It is unknown if this species is very rare in this area or if is being misidentified with Galeus melastomus or Galeus polli that also occurs in the same area.
|Habitat and Ecology:||Galeus atlanticus is a demersal species with a reported to occur at depths of 400 to 600 m (Compagno et al. 2005) and extended to 330 to 710 m by Rey et al. (2005). There is one record at depths between 0 and 50 m reported from the MEDITS survey (Baino et al. 2001). Bauchot (1987) measured a mature female of 39.8 cm and a male of 38.4 cm TL. Compagno et al. (2005) report female size at maturity between 40 and 45 cm TL and for males ~38 to 42 cm TL. Maximum size is ~45 cm TL (Compagno et al. 2005). This species is oviparous, eggs are protected by an horny case 11 to 13 mm by 38 to 40 mm in size (Bauchot 1987), with apparent multiple ovipary (nine eggcases reported in one female) suggesting a short hatching period outside the mother (Compagno et al. 2005). In the western Mediterranean, where this species is found in the Alboran Sea, it captured from 330 to 790 m depth, but mostly between 500 to 600 m depth, with sizes ranging from 18 to 42 cm TL in males and 20 to 45 cm TL in females (Rey et al. 2005). At present more information is required on its population dynamics parameters.|
G. atlanticus is still recorded as G. melastomus for fishery data (due to its external similarity it is very difficult to separate the two species). The species is caught as bycatch by trawl nets and bottom longlines on slope bottoms. Accessory species in the semi-industrial and artisanal fisheries with trawl net, gillnet, longline (Bauchot 1987). Caught as bycatch by bottom trawls and artisanal fisheries (Serena 2005).
Where this species is most frequent in the Mediterranean Sea (Alboran Sea) is very heavily fished by deep water trawlers targeting crustaceans such as Norway lobster (Nephrops norvegicus) and red shrimp (Aristeus antennatus). These trawlers operate throughout the depth range and area of occupancy of this species in this region. Therefore it is probably being captured as by-catch within all its narrow range of occurrence in this region.
This species is only known to occur from the Straight of Gibraltar to the southwest coast of Portugal in this region. Off the south coast of Portugal (Algarve), it is captured as bycatch of the deep water longline fishery that targets wreck fish Polyprion americanus and conger eels Conger conger and by deep water trawlers targeting crustaceans such as Norway lobster Nephrops norvegicus, red shrimp Aristeus antennatus and pink shrimp Parapenaeus longirostris. Most of the specimens are discarded, although the larger specimens have some commercial value and can be sold for human consumption. Most of the discarded specimens are still alive when returned to sea, but usually have severe injuries that are likely to impair their survival (R. Coelho pers. comm. 2006). In Portuguese fisheries statistics, marketed specimens of this species are mixed with Galeus melastomus and recorded as Galeus melastomus, making it impossible to discriminate trends of commercial captures through time. Currently, all the narrow area of occurrence in the Northeast Atlantic is being heavily fished either by deep water trawlers or deep water longliners, so the entire population in this region is likely suffering fishing mortality.
Off cape Spartel, in the area where the type specimen has been recorded, there has been a deep water longline fishery since 2001 targeting black scabbardfish (Aphanopus carbo) that is operating in the depth range of this species. In this area, there is also a deep water trawl fishery targeting crustaceans, of around 55 boats that also fishes within this specie's depth range (M. Hicham pers. comm. 2006). Both these fisheries may be taking this species as by-catch but these data are not recorded.
|Conservation Actions:||None currently exist. Given the restricted range of this species and that the fact that all the population is currently suffering fishing pressure (by-catch), this species should start to be monitored. Fishery observers should start separating this species from the very similar G. melastomus and G. polli.|
|Citation:||Coelho, R., Rey, J., Serena, F. & Mancusi, C. 2007. Galeus atlanticus. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 01 August 2015.|
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