Blackfish of Galapagos

Category: Blackfish
Family: Delphinidae

Five species or Blackfish have been recorded in Galapagos. The blackfish include the largest members of the dolphin family: the killer and pilot whales. They are predominantly black with conspicuous dorsal fins. The jaws contain many well-developed conical teeth, but the beak is small or lacking. Like other dolphins they are highly social, fast and acrobatic, often breaching, spy-hopping and lobtailing. They are extremely effective and powerful pack-hunters, able to catch fish, squid, and in some cases, marine mammals.

SHORT-FINNED PILOT WHALE

Identification: The Short-finned Pilot Whale is one of the easiest species to identify due to its characteristic shape and behavior. On surfacing, the bulbous, rounded head precedes a robust body with a dorsal fin set well forward. Behind the dorsal fin is a pale 'saddle patch' followed by a long back and tail stock. In both sexes the dorsal fin is very broad at the base, but this is especially so in adult males which have a large, flag-shaped fin. Because they tend to feed at night, most of the day is spent either travelling at a leisurely pace or logging.

Scientific Name: Orcinus orca

Adult Length: 5-9 m (16 - 30 ft)
Blow: Tall and bushy
Breaching: Leaps vertically
Group size: Family groups of 2 - 30

Frequent inshore and offshore, often seen during a Galapagos cruise.

Identification: The largest of the dolphins and perhaps the most distinctive cetacean of all. The striking black body, white eye-patch and prominent dorsal fin are unmistakable. Dorsal fin size and shape varies with age and sex. Adult males possess triangular fins which can reach up to 2 m in height. Females and immatures have smaller, sickle-shaped fins. Known to hunt other marine mammals including Sea lions, Sperm Whales and Bryde's Whales in Galapagos.

FALSE KILLER WHALE

Scientific Name: Pseudorca crassidens

Adult Length: 4-6 m (13 - 21 ft)
Blow: Insconpicuous and bushy
Breaching: Frequent, various angles
Group size: 2 - 200

Occasional offshore and inshore

Identification: Similar in shape to Melon-headed Whale and Pygmy Killer Whale but much larger and more powerful. Confusion is perhaps most likely with female Orca or Short-finned Pilot Whale. With good views the all-dark body distinguishes it from the former, and its slender, rounded head and body, with a dolphin-like dorsal fin, separates it from the latter. The position of the dorsal fin also differs from that of the Pilot Whale, being set further back at the mid-point of the back. At the surface False Killer Whales are often highly active swimmers, lifting their whole heads and bodies out of the water whilst travelling. Known to attack other cetaceans, including Sperm Whales, in Galapagos.

MELON-HEADED WHALE

Scientific Name: Peponocephala electra

Adult Length: 2 - 2.7 m (6.5 - 8.9 ft)
Blow: Generally not visible
Breaching: Occasional
Group size: Generally 50+

Rare offshore

Identification: This small, slender species is akin in size and shape to most dolphins. However its all black coloration and lack of a prominent beak distinguish it. Confusion is most likely with the Pygmy Killer Whale which is extremely similar. Close views in good light are required but there are several subtle differences. Perhaps most diagnostic is head shape which is slightly pointed or 'melon-shaped'. Other differences include slimmer and more sharply pointed flippers, lack of a dark cape, and a short but distinct beak, often present on females and juveniles.