Fish Identification: Dolphins (Part I)

I thought we'd do something a little different today. Everyone is familiar with dolphins in some shape or form, but did you know there are 18 genera (plural of genus) of oceanic dolphins? We are going to cover some of the more common ones. Then you can look smart when someone shouts "Dolphin!" and say, "More specifically, that's a Pacific white-sided dolphin."

Common Dolphin

Common dolphin

It's called the common dolphin, but is probably not the most familiar. There are over 20 species of common dolphin, in all shapes, sizes, and colors. Generally speaking, the common dolphin has a dark back with a white underbelly. Two of the most common variety are the long-beaked and short-beaked. These, like many dolphins, are found in pods of 10-50.

Bottlenose dolphin

Bottlenose Dolphin
If a dolphin should come to mind when you hear "common dolphin", it should actually be the bottlenose. This is the dolphin of pop culture (Flipper) and seen in marine parks worldwide. These are the one of the larger types of dolphin, and are seen the world over, everywhere except in polar waters.

They have a short, well-formed snout that resembles an old-fashioned bottle. They tend to be grey all over, with slightly lighter bellies. Bottlenose dolphins also have more neck flexibility than other dolphins, making them capable of all the expressions that they have become well-known for.

Right whale dolphin

Right Whale Dolphin
Right whale dolphins are predominantly black with small white underbellies. They are distinguished as being one of the only dolphins without dorsal fins.

Right whale dolphins tend to remain in the colder aquatic regions, although they have been spotted in warmer waters. They are divided into species of northern right whale dolphins and southern right whale dolphins. They can be distinguished based on their white patterns: southern right whale dolphins have white that extends further on their body, including their snout and flippers. If still unsure, you should also be able to tell the difference based on where you are in the world.

Killer whale

Killer Whale
The killer whale, or orca, is actually a dolphin. Not surprisingly, it is the largest oceanic dolphin. Killer whales are apex predators, and thus have no natural predators.

Killer whales probably need no description, but they have black backs, white chests and sides, and a white patch above their eyes. They range in size from 5-8 meters (16-27 feet).

There's probably not much you haven't heard about this group, so here's an interesting tidbit. To travel faster, killer whales will leap out of the water while swimming. This technique is called porpoising.

Next time we'll get into the more obscure dolphins.

Common dolphin photo by mikebaird
Bottlenose dolphin photo by The Pug Father
Killer whale photo by [*christopher*][]