Steno bredanensis


Rough-toothed dolphins are a tropical species inhabiting all oceans worldwide. It is rarely found in the northern Atlantic Ocean and only a few sightings have been recorded in the north east Atlantic.


Physical description and behaviour:

Adult rough-toothed dolphins measure between 2.5 m to 2.8 m length and have the typical delphinid body shape. Individuals does not have a demarcation between their melon and beak, which is fairly long. The species’ body colour is dark grey and turns white or pinkish on the belly area as well as the lower jaws and lips. The dorsal fin is slightly recurved and stands rather tall and erect. The flippers set further back than most dolphins, are dark grey like the back and are relatively large.

Little is currently known about this species’ behaviour globally, although more research seems to be currently undertaken especially in Brazil. They are believed to feed on fish and cephalopods (IUCN).


Distribution and abundance:

Rough-toothed dolphins are usually found in deep offshore waters but they may also be seen closer to the coast. They inhabit subtropical and tropical waters globally and there are very little population estimates.

There are only two – maybe three – records of rough-toothed dolphins thought to be in the ASCOBANS Agreement Area, namely from the Ghent area in Belgium (1825), one potential north of Paimpol in Brittany (1889) and a last one from Brest in Brittany (1983).


IUCN Red List of Threatened Species™ Assessment

  • LC (Least Concern) globally, last assessed in 2018
  • NA (Not Applicable) in European waters, last assessed in 2007



Bycatch or injuries from fisheries are thought to be the main threat, especially longlines, purse seines and drift gillnets (IUCN).


Assessment information
CMS InstrumentsASCOBANS, ACCOBAMS, Western African Aquatic Mammals, Pacific Islands Cetaceans
IUCN StatusLeast concern

No pictures for Steno bredanensis

Common names
EnglishRough-Toothed Dolphin
Scientific name Steno bredanensis
Other details
Additional notesUpdates have been made in August 2021 as per European Whales, Dolphins and Porpoises by Peter G. H. Evans (2020) unless stated otherwise.