Orcinus orca, Linnaeus, 1758

Identification

It is the largest member of the dolphin family. The distinctive black, white and gray marks and the enormous dorsal fin make it relatively easy to identify. They have a white patch behind the eye, a grey lumbar saddle-patch, large paddle-shaped fins and a robust and heavy body. They have sexual dimorphism. Males are longer and bulkier than females. There is a great difference in the size and shape of their dorsal fins, since the dorsal fin of the males is very large, and triangular and the dorsal fin of the females is smaller and more curved. 

Biology

The gestation period is 15-18 months and the calf is born with 180 kg and 2,1-2,5 meters. Adults can weigh between 2,6-9 tons and measure between 5.5-9.8 meters. The breeding interval can be five years. The orca is a versatile predator. They feed on squid, fish, birds and, occasionally, sea turtles, seals and dolphins.
They are observed more frequently in cold waters than in tropical or subtropical waters. They usually prefer deep waters, but are often found in shallow bays, inland seas and estuaries. The average life expectancy of this species is extremely long, since males reach 60 years of age and females reach 90 years of age.

Behavior

It is possible to find isolated animals, but they are usually found in cohesive family groups that remain throughout life. They are curious animals and they approach the boats. They rarely “Bow-Ride” or the “Wake-Ride” but are often observed breaching, lobtailing, flipper- slapping and “spyhopping” (they rise slowly out of the water to the head and most of the flippers remain above the surface). The pod often cooperate during a hunt. They can swim up to 55km/ h. The blow is low and bushy.