Cunning Cuttlefish
Cuttlefish are unusual animals. For starters, their blood is blue-green and they have three hearts. Their eyes are shaped like W’s. They have eight arms and two tentacles that spring from their head.
The cuttlefish name is misleading. A cuttlefish is not a fish at all. It is a mollusk. Think snail, slug, or clam. Millions of years ago, the cuttlefish had a hard shell, which provided protection from predators. But the cuttlefish has evolved into a soft-bodied animal. Today it has other ways to stay safe.
This is the pharaoh cuttlefish (Sepia pharaonis).
A hooded cuttlefish swims along a coral reef at night.
Cuttlefish are the chameleons of the sea. They frequently and rapidly change their appearance to throw off enemies. Cuttlefish can change their skin color within seconds. It can change from black to brown to yellow. It can look spotted. It can also look striped. Cuttlefish can even change the texture of their skin. It can go from smooth to rough.
Cuttlefish have millions of special color cells in their skin that allow them to appear in so many different patterns and colors. Scientists who have studied cuttlefish are amazed by their ability to match their surroundings. In one experiment, scientists placed cuttlefish in front of different backgrounds. They discovered that even small changes to the background would lead to changes in the color and patterns of the cuttlefish’s skin.
The cuttlefish’s skin helps it hide from predators. It also helps the cuttlefish hunt. When the prey gets close, the cuttlefish quickly snatches it.
The Cuttlefish’s changing skin has other advantages as well. Large male cuttlefish change colors to attract females. But the smaller male cuttlefish change their colors to look like females. This lets them get closer to the female cuttlefish without being challenged by the bigger male cuttlefish.
There are more than 120 species of cuttlefish known. They can live in both shallow reefs and in deep ocean waters.
Their changing skin is not the only interesting thing about cuttlefish. These strange creatures are also considered one of the smartest animals of the sea. What makes them so brainy? According to marine biologist Jean Boal, cuttlefish can think and solve problems. Researchers created a maze to test the cuttlefish. And the cuttlefish were able to figure out the maze and get faster, too. Scientists have also found that they are capable of REM (rapid eye movement) during sleep. That means that these creatures dream. Scientists used to believe that only vertebrates could dream.
Scientists hope to learn more about intelligence in all animals by studying intelligence in cuttlefish. Boal has spent almost twenty-five years studying these creatures. “The cuttlefish might seem alien to us, but [they] could tell us more about ourselves than we realize,” she says.
A Special Link
Cuttlefish, like squid and octopus, can squirt out ink. The ink makes the water cloudy and gives the cuttlefish time to escape from a predator. Humans have long used this brown ink in art products. The color name “sepia” comes from the cuttlefish species name, Sepia officinalis. More recently, scientists have been experimenting with new uses from the ink. They have created a new battery that uses cuttlefish ink.
