Why False Killer Whales Are Not Whales

Also known as pseudorca or blackfish, false killer whales belong to the order Cetacea, and are actually members of the dolphin family, Delphinidae. An in-depth study of this species has not been carried out, thus, the information about them is limited, and has been gathered by studying the stranded ones.

Pseudorca crassidens, the scientific name of this whale, comes from the Greek word 'Pseud' meaning false and the Latin word 'orca' meaning 'some kind of whale.' Due to its resemblance to the killer whale, it is called the false killer whale. Crassidens is formed from two Latin words called 'crassus' and 'dens', which means 'stout' and 'tooth' respectively.

Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Cetacea
Family: Delphinidae
Genus: Pseudorca
Species: crassidens

False killer whales are mostly black in color, with some gray-white regions on the head and chest. Their bodies are long and slender, with conical heads, narrow foreheads, and no beaks.

Their dorsal fins are tall, falcate (curved backwards), and are situated midway down the animal's back. The pectoral fins or flippers feature a distinctive hump halfway down the front edge or leading edge. The flippers look like elbows, as in the case of long-finned pilot whales.

The average length of a male is 17.6 feet and that of a female is 15 feet. The longest male recorded was 20 feet long. They use sounds like those made by dolphins, in order to communicate with one another.

The false killer whale is actually a member of the toothed whale family, Delphinidae (dolphin family). Thus, scientifically, it's not a whale. When observed from a distance these animals look exactly like killer whales, however, when looked upon closely, you will find them more slender and darker in appearance.

However, it's not only the appearance that makes them similar to whales. These mammals, just like killer whales, hunt their prey by a technique called 'herding', wherein, a large group of false killer whales encircle the prey and pounce on it all at once.

Pseudorca crassidens is found in tropical, sub-tropical, and warm temperate waters. They are found dwelling in the Hawaii waters, as well as in the Atlantic Ocean, Pacific Ocean, and the Indian Ocean. They are also found in the Red and Mediterranean seas.

False killer whales prefer areas of deep water in the open ocean, however, sometimes, they are found mass stranding on the beaches. There is no information regarding the migratory patterns of this species, and accurate data regarding their population figures is also not available.

Their diet comprises a variety of fauna, such as squid, cephalopods, and a large variety of fish. They are also known to attack smaller dolphins and whales, and are notorious for attacking the 30 kg yellowfin tuna from longline fishing operations. These species are known to hunt their prey by a process called herding, and thus are efficient pack hunters.

Their reproductive habits are not known, however, it is believed that their breeding season lasts for several months. The males reach sexual maturity at 18 years, while the females take 10 years to become sexually active.

The reproduction rates are low, with a period of approximately seven years as the calving interval. Thus, they rely on high survival rates to balance their population ratios. The females ovulate once annually, and after fertilization, the gestation period corresponds to 14 - 16 months.

Interestingly, these animals are gregarious, and are observed to form strong social bonds. They form groups called pods, comprising 40 to even 100 individuals, and travel in large bands in search of prey. They are even seen to mass strand on the beaches.

On January 11, 1970, around 175 - 200 false killer whales beached themselves in Florida, and refused to move back into the sea. Volunteers tried to coax them into going back, but with no avail. The whales eventually died on the beach. The reason for this strange behavior is still unknown.

These marine animals are not hunted commercially, however they end up as bycatch off the coast, where long-line fishing for tuna and swordfish are carried out. Their beaching behavior is peculiar and intriguing, and although the cause is unknown, let's hope that scientists are able to decipher this mystery soon!