There are two records of this species from the northwest coast of Cuba (L.J.V. Compagno pers. comm. 2007).
Madeira, Canary Islands, Portugal, France and in the Mediterranean Sea from Catalan Sea, Spain, France; Ligurian Sea off northern Italy; Sicily; Israel (L.J.V. Compagno pers. comm. 2007).
- Yano, K., J.D. Stevens and L.J.V. Compagno 2004 A review of the systematics of the sleeper shark genus Somniosus with redescriptions of Somniosus (Somniosus) antarcticus and Somniosus (Rhinoscymnus) longus (Squaliformes: Somniosidae). Ichthyol. Res. 51:360-373. (Ref. 50224)
- Cox, G. and M. Francis 1997 Sharks and rays of New Zealand. Canterbury Univ. Press, Univ. of Canterbury. 68 p. (Ref. 26346)
- Stocks, K. 2009. Seamounts Online: an online information system for seamount biology. Version 2009-1. World Wide Web electronic publication.
Habitat and Ecology
Attains a maximum size of about 140 cm total length (TL); size at birth is between 21 and 28 cm TL; males are mature at 71 cm TL and females at 80 cm (Compagno et al. 2005). Reproduction is aplacental viviparous, with 8–17 pups per litter (Tortonese 1956, Barrull and Mate 2002, Compagno in prep.). Reproductive age, periodicity, gestation time, rate of population increase and natural mortality are unknown.
This species feeds on mesobathyal cephalopods such as Histiotheuthis spp. and Todarodes sagittatus (J. Guallart pers. obs. 2007). Although specimens of this species are usually captured with bottom fishing gears, the finding of these highly-mobile cephalopods in the stomach contents may be interpreted as an indicator that S. rostratus moves throughout the deeper reaches of the water column, a propensity that may partially explain the scarcity of captures in deep demersal fisheries.
- Compagno, L.J.V. 1984 FAO Species Catalogue. Vol. 4. Sharks of the world. An annotated and illustrated catalogue of shark species known to date. Part 1 - Hexanchiformes to Lamniformes. FAO Fish. Synop. 125(4/1):1-249. Rome: FAO. (Ref. 247)
Depth range (m): 683 - 683
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From 200 to 1000 meters.
Life History and Behavior
Molecular Biology and Genetics
Statistics of barcoding coverage: Somniosus rostratus
Public Records: 0
Specimens with Barcodes: 2
Species With Barcodes: 1
IUCN Red List Assessment
Red List Category
Red List Criteria
Intense deepwater fisheries operate in areas of the northeast Atlantic. For example, a target fishery for deep-water squaloid sharks operated off Portugal at depths of 800–1,400 m since 1992 (DELASS 2003). Catches decreased rapidly and, by 1996, only one longliner was engaged in it at full time. Most of the catch consists of Centrophorus granulosus, though other deep-water species such C. squamosus and C. coelolepis are also caught in small quantities (DELASS 2003).
This species is also a bycatch of the general demersal and black scabbardfish fisheries in the Azores, although species-specific data are not available (DELASS 2003). A recent ban on bottom trawling below 1,000 m in the Mediterranean Sea (see Conservation Measures) may afford this species some protection, particularly if it is mainly distributed at greater depths. However, the species is still vulnerable to capture in fisheries in the upper half of its bathymetric range.
This species may be slow growing and slow to mature, like other deepwater Squaloid sharks, making it vulnerable to population depletion in fisheries. The relatively small range of this species, compared to most other sleeper sharks, and rarity in an area, which has been subject to very heavy fishing pressure for a long period, is of concern (L.J.V. Compagno pers. comm. 2007).
The General Fisheries Commission for the Mediterranean (GFCM) banned bottom trawling below depths of 1,000 m in the Mediterranean in February 2005 and this came into force in September 2005. The measure was adopted by consensus by all members of the GFCM, which include: Albania, Algeria, Bulgaria, Croatia, Cyprus, EC, Egypt, France, Greece, Israel, Italy, Japan, Lebanon, Libya, Malta, Morocco, Romania, Slovenia, Serbia and Montenegro, Spain, Syria, Tunisia, and Turkey.
Like many deeper water species more information on biology, ecology and population trends are required to fully assess the status of this species and any future conservation needs.
The development and implementation of management plans (national and/or regional e.g., under the FAO International Plan of Action for the Conservation and Management of Sharks: IPOA-Sharks) are required to facilitate the conservation and management of all chondrichthyan species in the region.
Relevance to Humans and Ecosystems
Little sleeper shark
The little sleeper shark, Somniosus rostratus, is a sleeper shark of the family Somniosidae found in the northeast Atlantic, western Mediterranean, and western Pacific around New Zealand, at depths of between 200 and 1,000 m. Its length is up to 1.43 m.