Dwarf sperm whale
Small, sturdy cetaceans that are easily confused with Pygmy sperm whales. Characteristic features which help distinguish the species from the Pygmy sperm whales is the more prominent and slightly falcate dorsal fin which is set farther towards their head, which is more conical than that of the Pygmy sperm whales.
They are rarely sighted so most of the existing data originates from dead (stranded) individuals. Their blowhole is on the left side of their body and their spout is practically invisible. At least two genetically different species are known and all possess a spermaceti organ. They reach sexual maturity at age of 4-5 years
Special feature: like the Pygmy Sperm Whales, they too expel a dark reddish-brown liquid (intestinal substance), when startled. The liquid creates a dense cloud that may parry a predator and supports the whale’s escape.
Further names: Portuguese: Cachalote-anão
Size of adults: up to 2,7 m
Prey: Cephalopods, fish and crustaceans (shrimps and crabs).
Behaviour: Very timid animals so little is known about their social life. When encountered they are either alone or in small groups of up to ten animals. Lethargic movement with a tendency to simply drift motionless at the surface. Sometimes animals allow slow approach of boats. When diving they sink down like a stone, without raising their flukes.
Range: Tropical and temperate waters worldwide usually at continental shelves. No evidence on migration.
Madeira: Very rarely sighted
Distinctive features: superficial resemblance with sharks; head with very little underslung lower jaw and “false gill” (a light bracket-shaped marking between the eye and flipper), pointed, falcate dorsal fin.
Taxonomy: Suborder: Odontoceti (Toothed whales); Superfamily Physeteroidea (Sperm whales); Family: Kogiidae
Threats: Climate change, marine waste, increasing underwater noise level. Insufficient data on population levels.