Rough-Toothed Dolphin (Steno bredanensis)


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Get your copy of “Albert the Orca Teaches Echolocation to The Super Fins” beginning March 2017 at

Rough-toothed dolphins are small members of the dolphin group that can grow up to 8.5 feet (2.6 m) long and about 350 pounds (160 kg).

They have a small head with a long beak with no crease at the melon. Their dorsal fin is relatively large and tall and is located at the mid-back and they have relatively long flippers (pectoral fins). Body color is dark with white lips and throat and a dark dorsal cape that is narrow between the blowhole and dorsal fin. The belly (ventral) surface has irregular spots and blotches.

Reproductive biology is poorly known in this species, but it is known that maturity occurs at 11 years of age and maximum longevity is 32 years.

Rough-toothed dolphins usually occur in tight-knit groups of 10 to 20. They often associate with other dolphins including short-finned pilot whales, bottlenose dolphins, pantropical spotted dolphins, and spinner dolphins. They apparently feed primarily on squids and fishes.

This species is classified as LEAST CONCERN according to the IUCN's Red List.
This species is classified as LEAST CONCERN according to the IUCN’s Red List.


MMPA – Rough-toothed dolphins, like all marine mammals, are protected under the MMPA.
CITES Appendix II – throughout its range

Species Description

350 pounds (160 kg)
8.5 feet (2.6 m)
dark with white lips, they have a small head with a long beak
32 years
squids and fishes
usually occur in tight-knit groups of 10 to 20, and they often associate with other dolphin species

RELATIVE SPECIES: Bottlenose dolphins, spotted dolphins, spinner dolphins

NEIGHBORING SPECIES: Bottlenose dolphins, spotted dolphins, spinner dolphins.


THREATS: Taken in fishing gear

DIET: Fish and cephalopods

MANNER OF FEEDING: Will cooperatively catch fish. They often share fish that are large. They are known for stealing fish from fishermen.

BEHAVIOR: Close-knit groups of 10-20. Travel with other types of dolphins and whales. Can dive very deep.

REPRODUCTION: Become sexually mature at 11 years.

LIFE SPAN: 32 years


Rough-toothed dolphins prefer deeper areas of tropical and warmer temperate waters where their prey are concentrated.


Rough-toothed dolphins are found primarily in deep waters throughout tropical and warmer temperate areas of the world. There are two recognized stocks in the U.S.: Hawaii and Northern Gulf of Mexico.

Population Trends

The most recent stock assessment reports with population estimates are available on our website.


  • few are “taken” in drive fisheries
  • some bycatch in gillnet fisheries; though there is no reported bycatch from U.S. fisheries, they are known to take bait in fisheries in Hawaii

Conservation Efforts

There are no known conservation efforts directed specifically at this species as they are poorly known and have few fishery interactions, and there are no other known threats.

Regulatory Overview

This species is protected under the Marine Mammal Protection Act of 1972 as amended.


Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Cetacea
Family: Delphinidae
Genus: Steno
Species: bredanensis


  • Rough-toothed dolphins have adapted well to captivity which is unusual for oceanic dolphins.
  • Rough-toothed dolphins can remain submerged for up to 15 minutes.
  • One of the few types of dolphins that can adapt to life in captivity.SOURCES:
  • Knopf, Alfred A. Guide to Marine Mammals of the World.Random House. 2002