Helping you keep your aquarium beautiful and healthy


Finding Nemo and Friend

Robert W. Bly, founder,

A few years ago, there was a popular animated movie, "Finding Nemo," about a young clown fish named Nemo. He becomes separated from his dad (voiced by Albert Brooks) and spends the movie trying to find and reunite with him, aided by a trigger fish voiced by Ellen DeGeneres.

The film inspired youngsters to beg their parents to buy them a clown fish. Perhaps not fully realizing that clown fish are saltwater fish, and that caring for a saltwater tank takes some work, these parents rushed out to please the kiddies, creating a boom in sales of clown fish and small salt water tanks.

Of course, neither the kids nor their parents had any intention of becoming marine aquarium hobbyists. The tanks were not properly cared for; clown fish died by the thousands, and the fad was soon over.

But whenever I have had marine aquariums, I always bought a clown fish and a sea anemone to keep it company. While sea anemones (like coral) look like plants, they are (also like coral) animals.

There are white, soft, short tentacles above the mouth at the top of the anemone. Most of the time, these are flaccid and sway gently back and forth with currents in the water.

Fish are attracted to the tentacles, thinking the anemone is perhaps an edible plant. When they get too close, the tentacles sting the fish, paralyzing it, and then draw the fish into the mouth where it is digested in an interior gastro-vascular cavity.

Clown fish are immune to the anemone's sting. They live among the tentacles in a sort of symbiotic relationship: the anemone's tentacles keep the clown fish safe from predators. In return, the clown fish help keep the tentacles clean by eating detritus.

I had my first clown fish and anemone pair years ago in a 29-gallon saltwater tank. They got along famously, and both lived a long time.

When you release the anemone into the marine tank, he will slowly sink to the bottom and find a place to root. Anemones attach themselves to rock, coral, or if the tank lacks objects, the sandy bottom.

If you have a filter vent inside the tank that draws up water, keep the anemone away from that when introducing him into the tank. Guide him gently to another place to root.

In my 92-gallon marine tank, my wife and son bought and added an anemone when I was not home. They emptied the bag containing the anemone into the tank.

He was pulled by the flow of water exiting the tank into the filter vent, and rooted over the plastic grating (the tank has a sump filter).

Concerned that he was blocking the filter from doing its work, my wife, acting in haste, pulled the anemone away to find another spot for him (we had rubber gloves we used to put our hands in the tank to protect ourselves against a lion fish we kept).

Pulling him away forcefully killed him. While anemones are not permanently rooted once they find a place to attach, and have slow mobility, they have to move under their own power. Their basal disk adheres to where they are rooted, and pulling them rips the fragile creature apart.

While clown fish always choose to live among the anemone tentacles, in a community marine tank, neither depends on the other for survival as do true symbiotes. The clown fish seemed not to miss his anemone partner, and went on living peacefully among our damsels and other small marine specimens.