Further names: Portuguese: Caldeirão; English: Slopehead, Steno
Size of adults: 2.1 – 2.6 m
Prey: Fish and cephalopods.
Behaviour: Despite them not being active at the surface, they are extremely powerful swimmers, often seen diving and resurfacing repeatedly in a synchronised manner in groups of two or more.
Range: Warm to tropical oceans, tend to prefer deeper water.
Madeira: Often encountered during the summer in small compact groups often containing calves.
Distinctive features: Relatively large teeth with fine longitudinal ridges align their jaws, covered by white to rosy lips. Their conical head with its relatively large eyes slopes smoothly into a slender beak with no demarcation. The back and the sides are dark grey with pale to rosy markings on the sides, their belly is white to rosy. They have a high, sickle-shaped dorsal fin that resembles that of Bottlenose dolphins at a distance. They have large flippers and flukes for their size.
Taxonomy: Suborder: Odontoceti (Toothed whales), Family: Delphinidae (Dolphins)
Threats: No reliable data on population size but estimates put the number of animals world-wide at around 150,000. This species is also under increasing pressure through fishing activity, noise pollution and the chemical pollution of the oceans.