|Scientific Name:||Centrophorus lusitanicus|
|Species Authority:||Barbosa du Bocage & de Brito Capello, 1864|
Centrophorus ferrugineus Chu, Y.-T., Meng, Q.-W. & A.-S. Hu and S. Li 1982.
|Taxonomic Notes:||Centrophorus lusitanicus, as described from Portugal, appears to relate to a large (> 1 m) heavy-built gulper shark. Specimens collected in the Eastern Indian Ocean and Western Central Pacific are a much smaller and slender species with a much longer first dorsal fin (W. White unpublished data). Centrophorus lusitanicus has been confused with C. niaukang in South African waters, and earlier accounts list the latter species under C. lusitanicus (e.g., Bass et al. 1975, Bass in Smith and Heemstra 1986, Compagno et al. 1989, L.J.V. Compagno pers. obs. 2007). Although the vessels the R.V. Algoa subsequently collected the 'real' C. lusitanicus from Mozambique waters along with C. niaukang, there is a question that the 'real' C. lusitanicus from various areas may be a species complex (L.J.V. Compagno pers. obs. 2007). Thus this species, pending further investigation, should be considered only from the eastern Atlantic (W. White unpublished data).|
|Red List Category & Criteria:||Vulnerable A2bd+4bd ver 3.1|
|Assessor/s:||Clarke, M., White, W. & Compagno, L.J.V.|
|Reviewer/s:||Acuña, E. & Valenti, S.V. (Shark Red List Authority)|
The Lowfin Gulper Shark (Centrophorus lusitanicus) is a deepwater shark distributed from Portugal, along the western African coasts, possibly to Cameroon in the eastern Atlantic. It occurs at 300?1,400 m depth, mostly between 300?600 m. Records of Lowfin Gulper Shark from elsewhere may be misidentifications. This species has been confused with the Taiwan Gulper Shark (Centrophorus niaukang) in South African waters, and specimens collected in the eastern Indian Ocean and western central Pacific are a much smaller and slender species. The 'real' C. lusitanicus from various areas may be a species complex. Therefore this species, pending further investigation, should be considered only from the eastern Atlantic from where it was originally described.
The Lowfin Gulper Shark's status is of concern because of its limited range, extremely low fecundity, and subjection to deepwater fisheries in the northeast and eastern central Atlantic. It is commonly confused with its congener Centrophorus granulosus. C. granulosus is estimated to have undergone declines of 80-95% where it is fished in the northeast Atlantic, and these declines may actually apply to both species. C. lusitanicus and C. granulosus are taken in deepwater fisheries operating off Portugal and in areas of their range in the Eastern Central Atlantic. Deepwater fisheries are expanding to greater depths off the western coast of Africa and declines in catches of deepwater sharks ?combined? have already been observed. The Lowfin Gulper Shark is a large, heavy-built species (possibly reaching lengths of more than 1 m) and may therefore be even more biologically vulnerable to depletion than other Centrophorus species (its longevity >30 years and only one pup is produced every two years) and there is no reason to suspect that this species will not also suffer declines where it is fished. The species is assessed as Vulnerable on the basis of inferred declines in areas where it is fished, balanced with areas of refuge from fishing pressure. Bycatch levels and fisheries should be monitored throughout The Lowfin Gulper Shark's range, and it may prove to warrant a higher category in the future, particularly as fisheries expand further across of its distribution. Species-specific monitoring of catch and population trends is urgently required for this biologically vulnerable shark.
|Range Description:||Northeast and eastern central Atlantic: Portugal, Morocco, Canary Islands, Senegal, Nigeria, Ivory Coast, Ghana, Gulf of Guinea, Cameroon (Compagno in prep). Records of this species from elsewhere may be misidentifications (see ?Taxonomy? for further information).|
Native:Cameroon; Côte d'Ivoire; Ghana; Guinea; Morocco; Nigeria; Portugal (Portugal (mainland)); Senegal; Spain (Canary Is.)
|FAO Marine Fishing Areas:||
Atlantic – eastern central; Atlantic – northeast
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Little specific information is available on the population of this species. However, information is available on population trends for the similar species, Centrophorus granulosus, which occurs within this species? range (see ?Threats? section).|
|Habitat and Ecology:||
Found over the outer continental shelves and upper slopes at depths between 300 and 1,400 m, and mostly between 300 and 600 m (Compagno in prep.). They have been taken at 370?610 m in the Eastern North Atlantic (Compagno in prep). It has also been reported at depths of 433?500 m off northern Mozambique, although this may refer to another species (Compagno in prep).
Little information is available on the biology of this species. Maximum size is about 100 cm total length (TL) (Compagno in prep.). A juvenile male and an adult male both measured 75 cm TL (Compagno in prep.). Four adult females (one pregnant) were 86?95 cm long (Compagno in prep.). Ovoviviparous reproduction, with one to six pups per litter (Compagno 1984). Size at birth is uncertain, but a near-term foetus was 33 cm TL (Compagno in prep.).
This species is of concern because of its limited range, extremely low fecundity and subjection to deepwater fisheries in the northeast and Eastern Central Atlantic (Compagno in prep.). This species is utilized in the eastern Atlantic, and captured there in bottom trawls and with fixed bottom nets and line gear (Compagno in prep.). It is potentially threatened in any area where there is a targeted fishery.
The Portuguese longline fishery which targets Black Scabbard Fish (Aphanopus carbo) at depths of 800?1,200 m off the coast of Portugal (ICES Subarea IX) takes a bycatch of the deepwater sharks, including Centrophorus species (ICES 2007). A Spanish longline fishery for Pagellus bogaraveo and a bottom trawl fishery off southern Portugal, which targets some deepwater crustaceans also take a bycatch of deepwater sharks (ICES 2007). In 2006 a new deep-water gillnet fishery was also initiated in this area and in waters northwest of Spain (ICES 2007). Off Portugal (ICES Subarea IX) the target species of this fishery are deep-water crab (283 tons) and several deep-water sharks (135 tons, plus 31 tons of livers and oil) (ICES 2007).
Identification problems mean that this species is commonly confused with its congener C. granulosus. C. granulosus is estimated to have undergone declines of 80?95% where it is fished in the northeast Atlantic. ICES (2006) landings data from the Portuguese coast show a strong estimated decline in C. granulosus catch from about 1,000 t in 1990 to less than 100 t in 2004 (Guallart et al. 2006). As C. lusitanicus is present along with C. granulosus in the Portuguese fishery it is highly likely that it has also been impacted. Centrophorus spp are very slow to mature, have extremely low fecundity and reproductive output, making them intrinsically very vulnerable to population depletion (longevity >30 years and one pup produced every two years). This is a large, heavy-built species (possibly reaches greater than 1 m length) and may therefore be even more biologically vulnerable to depletion than other Centrophorus species.
Deepwater fisheries also operate in the Eastern Central Atlantic and deepwater sharks are known to be targeted in some areas off Senegal. Off Kayar and Dakar, Senegal, an artisanal fishery targets Centrophorus species (including C. lusitanicus) for their liver oil (Direction des Pêches Maritimes du Sénégal 2007). The fishery uses gillnets to target deepwater sharks for part of the year. Fisheries are beginning to operate in deeper waters due to declines in catches of more coastal species (L. Mbaye pers. comm. 2007).
There is an upper slope fishery off Mauritania for hake that takes Centrophorus species as a bycatch (Fernandez et al. 2005). Important species within this group are Centrophorus granulosus, Centrophorus squamosus, Centroscymnus coelolepis, Centroscymnus crepidater, Dalatias licha, Deania profundorum, and Deania calcea. In their study of landed bycatch from this fishery from 1992?2001, Fernández et al. (2005) report that the catch of these squalids declined from 158 tons (87% of elasmobranch landings) in 1992 to 22 tons (59%) in 2001, with a minimum of 3.5 tons in 1999. The decline may be attributable to a set of factors, including a shift in the depths fished, economic reasons (the value and quality of elasmobranch landings fell during the period of the study) and probable over-exploitation of both the target and bycatch species. The fishery operates from 140?750 m depth, but currently tends to work at increasingly greater depths (with some variation according to the seasonal tides, and a recent average depth of up to 710 m per tide (2003 data from observers on commercial vessels)). Although this species is not currently reported from Mauritania, the trend for fisheries to expand into deeper waters in the Eastern Central Atlantic is of concern. Other fleets from Spain and other countries are also fishing in this area with both fresh and freezer vessels focusing on other demersal and semipelagic stocks, but little information is available to assess their impact on demersal stocks (Fernández et al. 2005).
|Conservation Actions:||No measures in place. It is recommended that species-specific monitoring of bycatch levels and population trends is carried out, as well as monitoring of fisheries expanding within its range.|
|Citation:||Clarke, M., White, W. & Compagno, L.J.V. 2009. Centrophorus lusitanicus. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 09 March 2014.|
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