Dwarf sperm whale
Kogia sima
biology
The Dwarf sperm whale is the smallest of all animals called "whales"—even smaller than many dolphins. Adults measure between 2.1 m and 2.7 m and weigh up to 275 kg. At birth, they are about 1 m long. Their lower jaw is small and subterminal (underslung), containing 7 to 13 pairs of extremely sharp, fang-like teeth. Occasionally, vestigial teeth are present in the upper jaw. Their lifespan is relatively short, with most individuals living around 20 years.
Their coloration is dark bluish-grey on the back and lighter, often pinkish, on the belly. Behind each eye, they have a pale, crescent-shaped mark known as a "false gill," which gives them a shark-like appearance when stranded. Their body is robust, and the head profile is somewhat rectangular or square when seen from the side. Unlike its cousin, the Pygmy sperm whale, the Dwarf sperm whale has a prominent, falcate dorsal fin located near the middle of the back.
A fascinating defense mechanism shared by the Kogia genus is the ability to release a cloud of reddish-brown intestinal fluid ("ink") when startled, creating a decoys to escape predators. They feed primarily on mid- and deep-water cephalopods, but also consume fish and crustaceans. These whales are often seen "logging" (lying motionless) at the surface, but they typically disappear by simply "sinking" underwater rather than rolling like other cetaceans.
Their coloration is dark bluish-grey on the back and lighter, often pinkish, on the belly. Behind each eye, they have a pale, crescent-shaped mark known as a "false gill," which gives them a shark-like appearance when stranded. Their body is robust, and the head profile is somewhat rectangular or square when seen from the side. Unlike its cousin, the Pygmy sperm whale, the Dwarf sperm whale has a prominent, falcate dorsal fin located near the middle of the back.
A fascinating defense mechanism shared by the Kogia genus is the ability to release a cloud of reddish-brown intestinal fluid ("ink") when startled, creating a decoys to escape predators. They feed primarily on mid- and deep-water cephalopods, but also consume fish and crustaceans. These whales are often seen "logging" (lying motionless) at the surface, but they typically disappear by simply "sinking" underwater rather than rolling like other cetaceans.
observation
The Dwarf sperm whale is primarily a tropical and subtropical species that prefers deep, oceanic waters. Much of what we know comes from strandings, as they are notoriously difficult to spot at sea due to their shy nature and inconspicuous blow.
Identification Challenges: Distinguishing between the two Kogia species at sea is a significant challenge. However, the Dwarf sperm whale is slightly smaller and can be identified by its larger, more erect dorsal fin positioned mid-back. Scientifically, the distance from the blowhole to the tip of the snout is less than 1/10 of the total body length in this species (whereas it is greater than 1/10 in the Pygmy sperm whale).
In the Azores, sightings are extremely rare. The only record for the Espaço Talassa team occurred in July 2013.
Identification Challenges: Distinguishing between the two Kogia species at sea is a significant challenge. However, the Dwarf sperm whale is slightly smaller and can be identified by its larger, more erect dorsal fin positioned mid-back. Scientifically, the distance from the blowhole to the tip of the snout is less than 1/10 of the total body length in this species (whereas it is greater than 1/10 in the Pygmy sperm whale).
In the Azores, sightings are extremely rare. The only record for the Espaço Talassa team occurred in July 2013.
names
PT: Cachalote-anão
ENG: Dwarf sperm whale
FR: Cachalot nain
DE: Kleiner Pottwal
IT: Cogia di Owen
ESP: Cachalote enano
NL: Kleinste potvis
ENG: Dwarf sperm whale
FR: Cachalot nain
DE: Kleiner Pottwal
IT: Cogia di Owen
ESP: Cachalote enano
NL: Kleinste potvis
Scientific name
Kogia sima
Discovery
Owen, 1866