Carcharhinus obscurus (Lesueur, 1818)
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Carcharhinus obscurus (Lesueur, 1818)
Genus: , ,

Scientific Name: Carcharhinus obscurus

English Name: Dusky shark

Creole Name:

French Name: Requin de sable

IUCN Red List Status: Endangered (EN)

Description:

Dorsal spines: 0; Dorsal rays: 0; Anal spines: 0; Anal rays: 0.
Large shark with moderately long and broadly rounded snout,labial furrows short and inconspicuous, triangular saw edged upper teeth. Large falcate first dorsal fin. 
1st dorsal-fin with origin over free rear tip of pectoral fin. Large curved pectoral fins tapering distally, apices pointed or narrowly rounded. Low inter-dorsal Ridge.
Colour. Blue-grey to lead-grey dorsally with most fin tips dusky, but not boldly marked. Underside white, inconspicuous white band on flank. 


Size:

Born 69-100cm. Maturity: males 265-280cm, females 257-310cm. Max. length 420cm.


Habitat and Ecology:

Continental and insular shelves from coastal to adjacent oceanic waters (depth 0-500m, usually below 200m). Juveniles in shallow waters.
Bony fishes are the primary prey, followed by elasmobranchs and crustaceans, with other species also taken.Viviparous, with a yolk-sac placenta. Females mate every 
2-3 years then move in shore to give birth after an estimated 16 months gestation. 2-18 pups per litter. 

Particularly vulnerable to overfishing due to life cycle characteristics of very late maturity and low reproductive rate. 


Fishery Status:

This species is not protected or subject to fishery regulations. Only one specimen was recorded in the artisanal catch during a 6-year survey period 
(Nevill, J.E.G. Shark fishery database) and constituted a new species record for Seychelles. It is likely more often caught in pelagic longline fisheries. 


Notes:

Only 1 specimen has been recorded in the artisanal catch to date (September 2014) and that had already been dressed, so the photos here do not include the head and 
the proportions are somewhat distorted by the removal of its internal organs.   


References:

Bray, D.J. (2017). Carcharhinus obscurus in Fishes of Australia, accessed 09 Aug 2021, https://fishesofaustralia.net.au/home/species/1953 (10/08/21)
Carcharhinus obscurus (Lesueur, 1818): In: Database of modern sharks, rays and chimaeras, www.shark-references.com, World Wide Web electronic publication, Version 08/2021.
Ebert, D.A. et al. (2013). Sharks of the World – A fully illustrated guide. Wild Nature press ISBN 978-0-9573946-0-5
Froese, R. & D. Pauly. Eds. (2021). FishBase. https://www.fishbase.de/summary/carcharhinus-obscurus.html (10/08/21)
Rigby, C.L. et al. (2019). Carcharhinus obscurus. The IUCN Red List 2019: e.T3852A2872747. https://dx.doi.org/10.2305/IUCN.UK.2019-3.RLTS.T3852A2872747.en. (10/08/21).


Citation:

Nevill, J.E.G. (2021). Carcharhinus obscurus, Dusky shark. Seychelles Seatizens. www.seatizens.sc . https://seatizens.sc/species/carcharhinus-obscurus-lesueur-1818/ (Updated 23/03/22)


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