|Scientific Name:||Etmopterus pusillus|
|Species Authority:||(Lowe, 1839)|
Acanthidium pusillum Lowe, 1839
|Taxonomic Notes:||The similar, but larger, Etmopterus bigelowi was previously confused with this species until described as a distinct species by Shirai and Tachikawa (1993) (Compagno in prep.).|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor/s:||Coelho, R., Tanaka, S. & Compagno, L.J.V.|
|Reviewer/s:||Acuña, E., Valenti, S.V., Kyne, P.M. & Fowler, S.L. (Shark Red List Authority)|
Etmopterus pusillus is a deepwater lantern shark that occurs in the Atlantic, Pacific and Indian Oceans, found on or near the bottom of continental and insular slopes at depths of 150?1,000 m, and possibly down to almost 2,000 m. The species is also oceanic in the central south Atlantic, and is found from the surface to 708 m depth over deepwater. Although E. pusillus is of little interest to global fisheries, it is a bycatch of bottom trawls operating in the eastern Atlantic and off Japan, fixed bottom nets, and line gear. It is discarded by fisheries off southern Portugal, but is probably a utilized elsewhere in the eastern Atlantic. In the Northeast Atlantic, although captures are still high and stable, very little is known about the biology and distribution of this deepwater species. More studies on this species? biology are needed; particularly considering that many deepwater squaloids have life characteristics that can make them especially vulnerable to depletion in fisheries. However, there is no evidence to suggest that this species has declined or faces significant threats. Furthermore it has a widespread geographic and bathymetric distribution and is therefore considered Least Concern at present. Expanding deepwater fisheries should be monitored and bycatch levels should be quantified to ensure that this species is not significantly impacted.
|Range Description:||Widespread, but patchy distribution in the Atlantic, Pacific and Indian oceans.
Western Central Atlantic: northern Gulf of México (USA, México). Southwest Atlantic: northeastern Brazil (States of Rio Grande do Norte, Pernambuco and Alagoas), southern Brazil, through Uruguay to Argentina. Central south Atlantic: oceanic between Argentina and South Africa. Northeast, eastern central and southeast Atlantic: Portugal, Madeira, Azores, Canary Islands, Liberia, Cape Verde, Ivory Coast to Gabon, Zaïre, Angola and Namibia. Western Indian: South Africa. Eastern Indian: Australia (Tasmania). Southwest Pacific: Australia (New South Wales) and New Zealand. Northwest Pacific: Japan (southeastern Honshu) (Whitehead et al. 1984, Last and Stevens 1994, Cox and Francis 1997, Soto 2001, Compagno in prep. a).
Native:Angola (Angola); Argentina (Buenos Aires, Chubut, Rio Negro, San Luis, Santa Cruz); Australia (Australian Capital Territory, New South Wales, Tasmania); Benin; Brazil (Alagoas, Bahia, Espírito Santo, Paraná, Pernambuco, Rio de Janeiro, Rio Grande do Norte); Cameroon; Cape Verde; Equatorial Guinea; Gabon; Ghana; Japan (Honshu); Liberia; Mexico (Tamaulipas); Namibia; New Zealand (North Is.); Portugal (Azores, Madeira, Portugal (mainland)); Sao Tomé and Principe; South Africa; Togo; United States (Alabama, Florida, Louisiana, Mississippi, Texas); Uruguay
|FAO Marine Fishing Areas:||
Atlantic – eastern central; Atlantic – northeast; Atlantic – southeast; Atlantic – southwest; Atlantic – western central; Indian Ocean – eastern; Indian Ocean – western; Pacific – eastern central; Pacific – northwest; Pacific – southwest
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Etmopterus pusillus is much less common than E. spinax, although it may occur within the same depth range off Morocco to Mauritania (Gulyugin et al. 2006). Catch per unit effort data are available from trawls conducted off Portugal in the eastern Atlantic, at depths of 84?786 m; abundance peaked at 400 m depth, with captures of 1.5 individuals per hour.|
|Habitat and Ecology:||
Etmopterus pusillus is found on or near the bottom of continental and insular slopes at depths of 150?1,000 m (possibly to 1,998 m); also oceanic in the Central South Atlantic from the surface to 710 m (Krefft 1980). In Moroccan waters, the species is subdominant and mainly occurs at depths of 400?600 m (Litvinov 1993). The species is very common in Sierra Leone waters at depths of 200?500 m (Litvinov 1993). In Cape Verde this species is frequently caught at Nova Holanda Seamount, Maio, Santo Antao, South Nocolau, and Sal, between 400?1,100 m, but usually from 650?750 m. In Suruga Bay, Honshu, Japan, mature and immature E. pusillus are segregated by depth. Immature sharks (16.5?32.7 cm TL) are captured by bottom trawl nets at depths of 150?411 m. Mature sharks (<42.3 cm TL) are captured on bottom longlines in deeper water (S. Tanaka pers. obs. 2007).
Very little is known about this species habitat, ecology and biology. Reproduction is aplacental viviparity. Total length (TL) at first maturity is 38?47 cm in females and 31?39 cm in males (Compagno in prep.). Data from off Portugal in the eastern Atlantic gives estimates of 38.1 cm TL for males and 43.6 cm TL for females (Coelho and Erzini 2005). Considering the observed maximum sizes of this population (47.9 cm for males and 50.2 cm for females), this species matures extremely late in its life cycle: 86.9% of the maximum size for females and 79.5% of the maximum size for males (Coelho and Erzini 2005). Size at birth (taken from final stage embryos) is 12.1?13.5 cm TL (Coelho unpublished data). Ovarian fecundity ranges from 8?18 eggs and uterine fecundity ranges from one to six embryos (Coelho unpub. data). In Suruga Bay, Honshu, Japan, female size at maturity is estimated at 47 cm TL and male size at maturity 38?41 cm TL (Shirai and Tachikawa 1993, S. Tanaka pers. obs. 2007).
Feeds on fish eggs, lanternfish, squid, and other small dogfish (Compagno in prep.). Off the coast of Namibia and South Africa, E. pusillus eats cephalopods, hake (Merluccidae, Merluccius spp.), lanternfish (Myctophidae, Diaphus), and small squaloid sharks (Compagno in prep.).
Although E. pusillus is of little interest to global fisheries, it is a bycatch of bottom trawls operating in the eastern Atlantic, fixed bottom nets, and line gear (Compagno in prep.). Although discarded by fisheries off southern Portugal, it is probably a utilized bycatch elsewhere in the eastern Atlantic. In Suruga Bay, Japan, this species is taken as bycatch by trawlnet fisheries and is usually discarded.
This species is captured in several fisheries off the southern Portuguese coast. Catch Per Unit Effort (CPUE) data for deep-water longlines set at 200?780 m depth have increased from 2.23 specimens of E. pusillus per 1,000 hooks (s.d.=2.72) in 1997?1998 (Erzini et al. 1999, Coelho et al. 2005) to 4.03 specimens per 1,000 hooks in 2003 (s.d.=2.30) (R. Coelho unpub. data). This represents an increase in CPUE of 80%. All samples were taken aboard commercial fishing vessels, where a number of variables cannot be standardized, namely the number of fishing days per specific depth, the number of fishing days per specific site, the number of fishing days per specific season, the size of the hooks and the bait used. Off southern Portugal, the species is also captured in high quantities as bycatch of the bottom trawl fishery that targets Norway Lobster (Nephrops norvegicus), Red Shrimp (Aristeus antennatus) and Deepwater Pink Shrimp (Parapenaeus longirostris), and by the near bottom longline fishery that targets European Hake (Merluccius merluccius), Conger Eels (Conger conger) and Wreck Fish (Polyprion americanus). Etmopterus pusillus are apparently discarded by all fisheries off southern Portugal, and therefore no landings data are available for these fisheries (Coelho et al. 2005).
Off the coast of western Africa (Namibia) in the southeast Atlantic, E. pusillus is caught occasionally in bottom and midwater trawls (Bianchi et al. 1999). The species is also presumably caught in deepwater trawls off Mauritania and Morocco as a result of the new silver scabbard deepwater longline fishery, which began in 2001, off Morocco (H. Masski pers. comm.).
Little information is available on the capture of this species in fisheries throughout the rest of its range, however these are not thought to pose a significant threat to the global population at present.
This species is utilized (dried-salted) for human consumption and for fishmeal in some areas (Compagno in prep.).
|Citation:||Coelho, R., Tanaka, S. & Compagno, L.J.V. 2009. Etmopterus pusillus. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 11 December 2013.|
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