Orcas are the largest member of the oceanic dolphin family. They can grow over 25 feet in length and weight as much as 6 tonnes (6.6 short tons).They are heavy bodied with large, paddle-shaped fins. Males typically have a straight, tall dorsal fin that can measure nearly six feet high.
Their unique coloration makes them quite easy to recognize. They are usually black above and white below, with a large white “eye” patch located just behind the eye and a gray “saddle” marking behind the dorsal fin. The “eye” patch can vary greatly in size and shape among different populations, as can the saddle.
Orcas are found in all of the world’s oceans. Across their broad range, there are many different populations which vary in how they look, what they eat, and their general behavior. In the North Pacific, for example, there are three main types: Residents, Transients, and Offshore. Meanwhile, in the North Atlantic, there are Type 1 and Type 2 orcas.
The cold waters of the Antarctic are home to four unique types of orca, all of which look quite different from each other. Type A orcas resemble a “typical” orca. Type B orcas are mostly gray instead of black, have very large eye patches, and a prominent saddle. Type C are the smallest, and are also mostly gray, with a very slanted eye patch. Both B and C types are often stained yellow in their white areas, which is thought to be due to algae called diatoms in the water. Type D are the most mysterious of the Antarctic orcas. They are rarely seen and have a very bulbous forehead, with a very small eye patch. Some scientists believe they may even be a completely different species of orca.