Description:

Large very thick set (massive) shark with very short bluntly rounded snout and large/long gills. Pale brown-grey to brown-grey on back lightening down the 
flanks to cream or off-white on the ventral surface. (Colour notably paler when freshly caught darkens shortly after death). A very pale grey, near white, (non-albino) 
specimen has been documented in Seychelles. Large dorsal fins and large, long triangular to semi-falcate pectoral fins. 
Fins: D1 large broad triangular to semi-falcate fin, plain coloured with medium length dorsal free tip. Apex pointed or sharply rounded. D1 origin over to half way 
posterior of pectoral fin insertion. (D1 less than 3.2 times the height of D2). D2 fin large and high with mid-sized dorsal free tip. Origin anterior to anal fin origin. 
No interdorsal ridge. Pectorals large and broad, triangular to semi-falcate, apices narrow and pointed with dusky tips on underside. Origin below posterior gill slits. 
Pelvic and anal fins typically have dusky tips.
Head: Thick-headed shark with very short bluntly rounded snout, eyes small and circular. Large triangular saw-edged upper teeth. Anterior nasal flaps broad based 
to triangular lobes. Upper labial furrows short and inconspicuous. Gill slits large.

Size:

Born 56-85cm TL. Mature: Male 155-225cm TL, Female 180-230cm TL, Maximum widely cited as 340cm TL (one record of 400cm TL – McCord & Lambeth 2009).

Habitat and Ecology:

Shark of coastal, insular and continental shelves. Known to utilise fresh water habitats also. Pups in brackish or freshwater environments 
(of particular note, a pregnant female Bull shark has been recorded travelling from the Amirantes to Madagascar to pup and then returning to the Amirantes – 
Lea et al 2015). Broad feeding niche: teleosts, invertebrates, turtles, sharks and rays, birds, marine and terrestrial mammals. Viviparous 1-16 pups per litter 
after a 10-11 month gestation. World record of 14 pups recorded in Seychelles (Nevill et al 2013) – with a litter of 16 recorded subsequently (Nevill 2014). 
In Seychelles pups in November-December.
 

Fishery Status:

This species is not protected. It is however illegal to fish for sharks with nets (Fisheries Act, Reg 16.c). It is caught in the hand line and 
particularly the short anchored long line fisheries. It is also, particularly juveniles, caught in the illegal net fishery. 

Notes:

In Seychelles the Bull shark, judging from artisanal catch returns, is the last truly apex predator resident in numbers on the Mahé plateau. Status and trends of the local 
population and its range are unknown.

References:

Ebert, D.A. et al (2013). Sharks of the World – A fully illustrated guide. Wild Nature press ISBN 978-0-9573946-0-5
Fisheries Act 2014. Prohibition of net fishing of sharks, Reg. 16c of 1st August 1998. (Carried over from the 1986 Fisheries Act as per Fisheries Act 2014 para 79: Savings and Transitional provisions).
Froese, R. and D. Pauly. Eds. (2018). FishBase. http://fishbase.org/summary/Carcharhinus-leucas.html (26/05/19).
Lea, J.S.E. et al (2015). To Madagascar and back: long-distance, return migration across open ocean by a preganant female bull shark Carchahrhinus leucas. Journal of Fish Biology (2015) 87, 1313-1321.
McCord, M.E. & S.J. Lamberth. (2009). Catching and tracking the world’s largest Zambezi (bull) shark Carcharhinus leucas in the Breede Estuary, South Africa: the first 43 hours. Afr. J. Mar. Sci. 31(1):107-111.
Nevill, J.E.G. (2021). Artisanal Shark Fishery database.
Nevill, J.E.G. et al (2013). Record Litter Size for the Bull Shark, Carcharhinus leucas (Muller & Henle, 1839), Documented in the Seychelles. Western Indian Ocean J. Mar. Sci. Vol. 12, No. 1, p. 85, 2013.
Nevill, J.E.G. et al (2015). An identification guide for the sharks of the Seychelles Artisanal Fishery.
Rigby, C.L. et al (2021). Carcharhinus leucas. The IUCN Red List 2021: e.T39372A2910670. https://dx.doi.org/10.2305/IUCN.UK.2021-2.RLTS.T39372A2910670.en. (05/10/21).
Simpfendorfer, C. & Burgess, G.H. (2009). Carcharhinus leucas. The IUCN Red List 2009: e.T39372A10187195. http://dx.doi.org/10.2305/IUCN.UK.2009-2.RLTS.T39372A10187195.en. (26/05/19).

Citation:

Nevill, J.E.G. (2019). Carcharhinus leucas, Bull shark. Seychelles Seatizens. www.seatizens.sc. https://seatizens.sc/species/carcharhinus-leucas-muller-henle-1839/ (Updated 02/01/22)