Record Litter Size for the Bull Shark, Carcharhinus leucas (Muller & Henle, 1839), documented in the Seychelles

Abstract

On the morning of 25 September 2013, a large female bull shark, Carcharhinus leucas, was landed in Port Victoria, Seychelles. It had been caught on an anchored long line set the previous evening, within 100 m of the main fishing quay. The female exhibited an unusually large girth for this heavy-set species.

 

The shark was photographed (Fig. 1a) and morphological measurements taken. On dissection the shark was found to be carrying 14 late stage embryos which were likewise measured and photographed (Fig. 1b).  The adult female measured 276 cm total length (TL). The 14 pups, consisting of seven males and seven females, had a mean TL of 69 cm and a size range of 65-71cm TL. The pups’ teeth had yet to emerge from the gums suggesting parturition was not imminent. Leading international data sources, Fishbase (Froese & Pauly, 2013) and the IUCN Red List (Simpfendorfer & Burgess, 2009), cite the maximum litter size for C. leucas as 13 pups. Review of the authoritative compendia and literature that inform these databases (Bass et al., 1973, Garrick, 1982, Compagno, 1984, Fowler et al., 2005) confirmed this maximum litter size but indicated that the majority of litters number between 6-8 pups. Furthermore, the upper limit of 13 pups comes from a single reference (Bass et al., 1973) that was not categoric, but stated that the litter in question contained “either 12 or 13 pups”. This Seychelles record therefore constitutes a definitive new finding for C. leucas, extending the known parameters of its reproductive capacity.