Species Guide | Basking Shark (Cetorhinus maximus)
APPEARANCE
The Basking Shark is the second largest fish in our oceans, coming in after the whale shark, which is the largest. This massive fish has a large, grey body that can reach lengths of up to 12 meters1. You can often see its large, black, triangular dorsal fin moving slowly through the water, and sometimes the tail tip or snout may be visible above the waves as well. Basking sharks are typically seen swimming with their cavernous mouths wide open to catch their prey.
Diet
Even though Basking Sharks are the second largest fish in the sea, they feed on zooplankton, which are among the smallest organisms in the ocean. They filter these tiny creatures from the water by swimming slowly with their mouths open.
HABITAT
Basking Sharks travel enormous distances around the globe. They are commonly found around the coasts of the British Isles, particularly along the west coast of Scotland and the south-west coast of England and Wales. While they can be seen at any time of the year, they are most frequently spotted between May and September.
Behavior
The Basking Shark is a massive and fascinating creature, yet much about this elusive giant remains a mystery. Evidence from satellite tracking clearly shows that they migrate long distances in the winter.
Did You Know? Basking sharks were actively hunted in Scotland until 1994 primarily for the valuable oil found in their livers. This oil was utilized in various products, including cosmetics, perfumes, lubricants, and even as lamp oil.
Basking sharks reach sexual maturity between six and 13 years, at lengths of 4.6 to 6 meters, and breed every two to four years. Their estimated lifespan is around 50 years2,3.
Basking sharks are ovoviviparous, laying eggs which hatch inside their bodies. Their teeth may help them feed on the mother’s unfertilized eggs, a behavior known as oophagy.
Gestation is thought to last over a year, possibly two to three years, with young measuring 1.5 to 2 meters at birth. Mating occurs in early summer, with birthing in late summer as females move to shallow waters.
STATS
| Body Length1 | 12 m |
| Body Weight1 | 6 tonnes |
| Longevity2,3 | Estimated 50 Years |
NATURAL PREDATORS
Killer Whales, Great White Sharks & Sperm Whales have been discovered with parts of Basking Sharks in their stomachs, although it is unconfirmed whether they actively hunt Basking Sharks or that they have scavenged dead animals.
Conservation Status
The Basking Shark is recognized as an endangered species on the International Union for Conservation of Nature (IUCN Red List), highlighting its global vulnerability. In Scotland, this remarkable fish enjoys full legal protection, a status that has been in effect since 1998, affirming the commitment to its preservation.
Global
Conservation Status
References
- Archipelagos Wildlife Library. “Basking Shark ( Cetorhinus maximus )”. Archipelagos Wildlife Library.
- Born Free Foundation. “Basking Shark Facts”. Born Free Foundation.
- Wood, Gerald (1983). The Guinness Book of Animal Facts and Feats. Guinness Superlatives. p. 256. ISBN 978-0-85112-235-9.
