Act! Support Our Efforts
Ocean Conservation Marine Life Species Database Education+Careers Projects Contributors Photos Videos News Connect

Rough-toothed Dolphins, Steno bredanensis

Rough-toothed DolphinsRough-toothed DolphinsRough-toothed DolphinsRough-toothed DolphinsRough-toothed DolphinsRough-toothed DolphinsRough-toothed DolphinsRough-toothed DolphinsContribute Photos or VideoContribute Photos or Video

Description & Behavior

Rough-toothed dolphins, Steno bredanensis (G. Cuvier in Lesson, 1828), are named for their 20-27 teeth with faint ridges located in both their upper and lower jaws. Adults are up to about 2.8 m long. They are known to reach weights of up to 150 kg. Length at birth is currently unknown.

Their color varies by region within the species, but generally they are dark gray with light spots on their flanks. The ventral (under) side, lower jaw and lips are white and they have a darker marking that extends over their eyes to the upper part of their flanks. Like other marine species, rough-toothed dolphins may show scars resulting from encounters with other marine life such as sharks, squid, and other rough-toothed dolphins.

This species has a distinctive sloped head and indistinct beak. They have large flippers and a central dorsal fin. Rough-toothed dolphins may be confused with bottlenose, spinner, and spotted dolphins, all 3 of which are species that have been observed associating with rough-toothed dolphins.

Steno bredanensis is a gregarious species found in groups of 10-30 on average, as well as schools of up to 160 dolphins containing up to 8 smaller subgroups.

Like other dolphins, rough-toothed dolphins communicate and echolocate using clicks and whistles.

World Range & Habitat

Rough-toothed dolphins, Steno bredanensis, are most commonly found in tropical and subtropical deep waters from the western Pacific to the Mediterranean. They are rarely seen ranging north of 40° latitude or south of 35° latitude.

Rough-toothed dolphin

They have also been seen along the Atlantic coast of the United States, in the Caribbean, Gulf of Mexico, Mediterranean sea, eastern tropical Pacific, and Indian Ocean. Geographic distribution of this species in not well known.

Feeding Behavior (Ecology)

Rough-toothed dolphins, Steno bredanensis, feed on fish and squid and other cephalopods.

Life History

Female rough-toothed dolphins, Steno bredanensis, reach sexual maturity at about 10 years, males at 14 years.

Rough-toothed dolphin

Little is known about the reproductive habits of this species. A rough-toothed dolphin was bred with a bottlenose dolphin in captivity producing a hybrid offspring.

Conservation Status & Comments

Rough-toothed dolphins, Steno bredanensis, are hunted for food in some regions. They are harpooned in Japan and West Africa. Entanglement in fishing gear poses a threat, and rough-toothed dolphins have been reported caught in purse seines in the eastern tropical Pacific. Others have been reported caught in gillnet and driftnet fisheries in Sri Lanka and Brazil.

Pollutants have been detected in blubber analysis of rough-toothed dolphins in Hawaii.

References & Further Research

Jefferson, T.A., S. Leatherwood, and M.A. Webber, FAO species identification guide, Marine mammals of the world, Rome, FAO. 1993. 320 p. 587 figs.
Whale and Dolphin Conservation Society (WDCS)

Research Steno bredanensis » Barcode of Life ~ Taxonomy ~ BioOne ~ Biodiversity Heritage Library ~ CITES ~ Cornell Macaulay Library [audio / video] ~ Encyclopedia of Life (EOL) ~ ESA Online Journals ~ FishBase ~ Florida Museum of Natural History ~ GBIF ~ Google Scholar ~ ITIS ~ IUCN RedList (Threatened Status) ~ Marine Species Identification Portal ~ NCBI (PubMed, GenBank, etc.) ~ Ocean Biogeographic Information System ~ PLOS ~ SIRIS ~ Tree of Life Web Project ~ UNEP-WCMC Species + Database ~ WoRMS

Search for Rough-toothed Dolphins » ARKive ~ Flickr ~ Google ~ Creative Commons search ~ Wikipedia ~ YouTube

Feedback & Citation

Start or join a discussion about this species below or send us an email to report any errors or submit suggestions for this page. We greatly appreciate all feedback!

~^~ surface

Help Protect and Restore Ocean Life

Help us protect and restore marine life by supporting our various online community-centered marine conservation projects that are effectively sharing the wonders of the ocean with millions each year around the world, raising a balanced awareness of the increasingly troubling and often very complex marine conservation issues that affect marine life and ourselves directly, providing support to marine conservation groups on the frontlines that are making real differences today, and the scientists, teachers and students involved in the marine life sciences.

Show your support with a monthly donation today.

With your support, most marine life and their ocean habitats can be protected, if not restored to their former natural levels of biodiversity. We sincerely thank our thousands of members, donors and sponsors, who have decided to get involved and support the MarineBio Conservation Society.