Bull shark
A euryhaline requiem shark known for aggression and freshwater tolerance.
The bull shark (Carcharhinus leucas), also known as the Zambezi shark in Africa and Lake Nicaragua shark in Nicaragua, is a species of requiem shark commonly found worldwide in warm, shallow waters along coasts and in rivers. It is notable for its aggressive nature and its ability to thrive in both salt and fresh water, making it one of the few cartilaginous fishes reported in freshwater systems. Bull sharks are listed as vulnerable on the IUCN Red List, with populations continuing to decrease partly due to shark-culling efforts near beaches.
Quick Facts
- Genus
- Carcharhinus
- Species
- leucas
Facts from the source article.
Lore & Background
The bull shark is named for its stocky shape, broad flat snout, and aggressive, unpredictable behavior. It has many local names, including Ganges River shark, Fitzroy Creek whaler, and Swan River whaler. The earliest fossil teeth of the bull shark are known from the Early Miocene of Egypt and Peru, becoming more widespread from the Middle Miocene onwards. Unlike river sharks of the genus Glyphis, bull sharks are not true freshwater sharks, despite their ability to survive in freshwater habitats; their similar physiologies are thought to have convergently evolved.
Reader's Guide
The bull shark's significance lies in its unique osmoregulatory capabilities, allowing it to travel far up rivers such as the Mississippi (as far as Alton, Illinois, about 1,100 km from the ocean) and the Amazon (up to Iquitos in Peru). It is responsible for a large part of nearshore shark attacks, with larger individuals implicated in many attacks involving unidentified species. Its aggressive nature has led to ongoing shark-culling efforts near beaches, contributing to its vulnerable status on the IUCN Red List. The species appears on the 2000 colones banknote from Costa Rica. Notable occurrences include bull sharks trapped in a golf course lake at Carbrook, Queensland, from 1996 to 2013, and sightings in flooded streets of Brisbane during the 2010–11 Queensland floods. The bull shark's bite force, weight for weight, is the highest among all investigated cartilaginous fishes.
Did You Know?
- Bull sharks have been recorded traveling up the Mississippi River as far as Alton, Illinois, about 1,100 km from the ocean.
- A single record exists of a female bull shark measuring exactly 4.0 m (13 ft).
- Bull sharks have a bite force up to 5,914 newtons, the highest weight-for-weight among all investigated cartilaginous fishes.
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