Risso's Dolphin

• anatomíaIts skin is usually covered in white scars, from fights with others of its kind and from struggles with the squid it mainly eats.
• Adults are covered in white scars caused by the teeth of other Risso's dolphins and by the beaks and suckers of squid; with age they come to look almost white.
• It has teeth only in the lower jaw, between two and seven pairs, because it swallows its prey whole.
• It is born dark grey and turns almost white with age, because it accumulates scars. The criss-cross scratches are made by other Risso's dolphins with their teeth, and the circular marks are left by squid, lampreys and the cookiecutter shark.
• It has two to seven pairs of teeth, and only in the lower jaw. That is an extremely low count for a cetacean, and it is thought to keep them mainly for their role in fights between males.
• It is a strict teuthophage: it eats almost exclusively squid, and hunts mostly at night.
• It dives to more than 600 m by emptying its lungs and descending almost vertically with several spins, a technique that saves it time and leaves it more minutes for hunting below.
• An individual called Pelorus Jack accompanied the ships entering Admiralty Bay, in New Zealand, for years, and came to be protected by a specific decree.
• It is the fifth-largest member of the dolphin family.

Skeleton type

Vertebrate - internal bony skeleton (mammal)

Habitat and environment

Temperate and tropical waters of every ocean, above all over the continental slope

Sexual maturity

10 years

Gestation / incubation

12 months

Litter / clutch size

1

Sources consulted: https://www.iucnredlist.org/ | https://animaldiversity.org/ | https://es.wikipedia.org/