Killer Whale Anatomy


Transcript

NARRATOR:

Orcinis Orca. They’re commonly known as the Killer whale because of their aggressive nature. But the Orca isn’t actually a whale: it’s in the dolphin family.

And while it shares a lot of the same characteristics of dolphins, the Orca has some unique features that are all its own, like its camouflage coloring. The Orca is counter shaded: black on the top and mostly white on the bottom. Looking down from above, the black on the dorsal side mixes with the dark ocean. Looking up from below, the white on the ventral side blends into the sunlit water. Other animals may not recognize a Killer whale until it’s too late.

Male Orcas have the largest dorsal fin of any marine mammal. It can get up to 6 feet tall. On females it’s a bit shorter and more curved. The dorsal fin acts like a keel, and each dorsal fin is unique for each Orca. The peduncle is the large muscular area between the dorsal fin and the flukes. The caudal peduncle is the part where the flukes meet the body. There aren’t any bones or cartilage in the dorsal fin and flukes. Instead, they’re made up of dense connective tissue. Longitudinal muscles in the back and caudal peduncle move the flukes up and down. The Orca’s pectoral fins are paddle-shaped. They’re used for steering and work in conjunction with the fluke for stopping. Inside these appendages is a network of veins that help regulate body temperature.

In between the dorsal fin and the peduncle is a grey swoosh known as the saddle patch. There are two types of saddle patches: open, which has more black in it: and closed, which has more white. The coloring varies depending on where the Orca lives. The eye is located just below and in front of the eyespot. Orcas have excellent eyesight in and out of the water. They also have a well-developed sense of hearing. And like other cetaceans, Orcas receive sound through receptors in their jawbones. The jawbone acts like a conduit, transmitting the sounds to the ear canal and auditory nerves.

Orcas also use echolocation. They create high frequency sound waves that are passed through the melon. The melon focuses these sounds and projects them into the water. The sound bounces off the objects and returns in the form of an echo. Just beneath the melon is the rostrum, and inside the rostrum are the Orca’s teeth. Orcas have anywhere form 40 to 56 interlocking teeth – each one around three inches long. They’re conical shaped and used for ripping and tearing, but not for chewing. Orcas eat their food in chunks or entirely whole.

Cetaceans are conscious breathers. They have to remember to take a breath every time they need air. Orcas breathe by opening the muscular flap of the blowhole. When closed, the blowhole is completely airtight. All of these parts working together make the Orca one ominous, awesome marine mammal.