Basking shark - Cetorhinus maximus

 

Illustration © Marc Dando

WHAT TO LOOK FOR
A very large shark with a pointed snout, huge mouth and gill slits that almost encircle the head, strong lateral keels on caudal peduncle, and a lunate tail.

COLOR
Variable. Darker above than below, often with a mottled pattern on back and sides with white blotches under the head.

SIZE
Males mature at less than 18 ft. [5.7 m], females at 26 ft. [8 m], maximum size 33 ft. [10 m].

HABITAT
Coast to edge of the continental shelf.

DISTRIBUTION
Worldwide in cold to warm temperate seas.

BIOLOGY

  • Prey – Plankton.

  • May shed gill rakers but no evidence for hibernation in winter.

  • Reproduction – One litter of six pups reported, presumably oophagous.

BEHAVIOR
Highly migratory. Often seen feeding on surface aggregations of plankton, moving slowly forward with open mouth. The sharks are sometimes seen in large groups. Complex courtship behavior has been reported. Can leap out of the water.

DISPOSITION
Generally placid but has been known to bump boats.

NOTE
This species is endangered regionally in areas where a targeted fishery existed. The Basking shark is listed as vulnerable on the International Union for Conservation of Nature (IUCN) Red List. It is protected in several countries, and in 2002 it was placed on CITES Appendix II.