Bull shark, Zambezi shark, Lake Nicaragua shark, River Whaler, Freshwater Whaler, Swan River whaler
German:
Bullenhai, Stierhai, Gemeiner Grundhai
French:
Requin bouldogue
Spanish:
Tiburón sarda
Appearance
Stocky to very heavy-bodied species. Very short and broadly rounded snout. Small, circular eyes. First dorsal fin large and broadly triangular to somewhat falcate. Origin of the first dorsal fin usually over or just behind the insertions of the pectoral fins. No interdorsal ridge.
Coloration
Pale to dark grey. Fin tips are dusky, but not strikingly marked. An inconspicuous white band on the flanks.
Distribution
Widespread along the continental coasts of all tropical and subtropical seas. Travels far up warm rivers (Mississippi, Amazon River, Zambezi River) and freshwater lakes (Lake Nicaragua, Lake Ysabel). Western Atlantic: Massachusetts to southern Brazil. Gulf of Mexico. Caribbean Sea, Bahamas. Eastern Atlantic: Morocco, Senegal to Angola. Western Indian Ocean: South Africa to Kenya, Iraq and India. Western Pacific: Thailand, Viet Nam, Borneo, New Guinea, Australia, New Caledonia, Fiji, Rangiroa Atoll, the Philippines. Eastern Pacific: Southern Baja California and Gulf of California to Ecuador.
Biology
Found close inshore in water less than 30 m deep and occasionally less than a meter deep, but ranging down to 150 m. It is the only shark that penetrates far into fresh water and apparently is able to exist there. Bull sharks are not able to maintain an entire life cycle in fresh water. In marine habitats this species commonly occurs in hypo- and hypersaline lagoons and bays.
Diet
Opportunistic feeder, with a very broad food spectrum. Favoured food includes bony fishes and elasmobranchs (rays and other sharks, sometimes even other bull sharks) but feeds on sea turtles, birds, and dolphins.
Size
Maximum about 340 cm (females); males reach about 300 cm.
Reproduction
Viviparous, with a yolksac-placenta. Gestation period is between 10 and 11 months. 1 to 13 pups per litter. Size at birth between 55 and 80 cm. Pups show a very slow growth rate. Males mature between 160 and 230 cm, females mature between 180 and 230 cm. Expected life span at least about 14 years.
Similar Species
None.
Vulnerability
Category:Vulnerable (VU) Criteria:A2bcd Last evaluated:2021 Trend:
Danger to Humans
Probably the most dangerous species of tropical waters. Bull sharks are one of the three most dangerous species, beside the Great white shark and Tiger shark It would not be surprising if the bull shark would turn out to be the most dangerous shark species, because of its large size, massive jaws, proportionately very large teeth and abundance in the tropics.
