by Kathy Kranking
Usually, a sea anemone (uh-NEM-oh-nee) like the pink one at left would be a little fish's worst nightmare. It uses its stinging tentacles to capture fish. Then it eats them up! But don't worry—the anemone won't hurt these fish! They're clownfish—BFFs with anemones! To find out more, read on.
BEST FRIENDS FOREVER
Clownfish are also called anemonefish, and there are 28 species of these anemone-dwellers. So why are clownfish safe from an anemone's tentacles? It's because these fish are covered with a layer of mucus that keeps the anemone from stinging them. For the clownfish, there's no better place to stay safe from hungry fish than among the tentacles of a fish-eating anemone! It's as if the anemone were a "bodyguard" for the clownfish.
There's another benefit to living with an anemone: free food! When the anemone catches fish to eat, the clownfish get to gobble up bits of its leftovers.
But the clownfish aren't the only ones benefitting from this relationship. This "friendship" is good for the anemone, too. The clownfish keep the anemone clean by eating up leftover food bits. They also eat any little pests that might try to live among the anemone's tentacles. And they chase away the anemone's enemies, such as butterflyfish, which can eat the tentacles without being harmed.
So for both the anemone and the clownfish, being BFFs is a good deal!
The false clown anemonefish above left is the same kind as Nemo, the famous movie fish. Sea anemones can close up, pulling all their tentacles insidse their bodies. When they do, the fish that live in them are pulled inside, too. But that's no problem for them—they're perfectly comfortable getting cozy among the anemone's tentacles, as are the two pink anemonefish above right.
The spinecheek anemonefish is named for the spines below its eyes (top left photo). A saddleback anemonefish would fiercely chase most creatures way from its anemone. But it lets the little cleaner shrimp on its head give it a "spa treatment" (bottom left photo).
A small group of clownfish will often live together in one anemone. The biggest fish is a female, and the next-biggest is her mate. A few other, younger fish may live in the anemone as well.
Clownfish pairs may stay together for years. But if something happens to the female, an amazing thing takes place: Her mate changes into a female and takes the missing female's place! Actually, all clownfish start as males and turn into females only if they become the largest fish in the group.
A female clownfish lays her eggs near the base of the anemone. The father clownfish guards the eggs, chasing off any fish that come near. He fans the eggs with his fins to keep water flowing around them so fungus can't grow on them. And he uses his mouth to clean around them.
Once the baby clownfish have hatched from their eggs, they float off and spend about 10 days or so drifting. They are mostly see-through at this time, which may help to hide them from predators. But then they settle to the bottom and change to their clownfish colors. That's when they start looking for anemones of their own to live in.
When a young clownfish finds an anemone, it has to get the anemone used to it. First the clownfish brushes its fins against the tentacles. Then it gradually touches them with outer parts of its body for longer and longer periods of time. This is how the clownfish and the anemone get to "know" each other. It's the beginning of another beautiful friendship!