Whitsunday Clown Fish

Clown Fish of the Whitsundays

On most dives or snorkelling forays in the Whitsundays you will encounter Clownfish. These colourful characters are quite litteraly full of character and highly entertaining. An entire dive can be spent watching over the life and goings on of a particular anenome and it's resident clown fish.

Most anenomes have a resident group of clown fish. The largest Clownfish will be the dominant female and the second largest will be the dominant male. These two will produce many eggs every month to replenish their species. Every month as breeding time comes about, the males will compete agreessively and prepare areas for a clutch of eggs. Should a male be fortunate enough to be chosen for breeding, he will be responsible for gaurding and hatching the eggs. The males are aggressive towards each other, sometimes to the point of driving one of the males off to another anenome. Should the dominant female die, a male will change sex and become the dominant female, this sex change is usually performed by the dominant male.

Clownfish are native to the Great Barrier Reef and other warm water coral reefs of the world. Clownfish feed on small invertebrates which otherwise could harm their host sea anemone, and the fecal matter from the clownfish provides nutrients to the sea anemone. Clownfish are omnivores. Algae accounts for around 20 to 25 percent of its diet in the wild (and should also account for its amount of algae diet in captivity as well). It has also been suggested that the activity of the clownfish results in greater water circulation around the sea anemone. In addition to providing food for the clownfish, the sea anemone also provides safety due to its stinging tentacles.

Clownfish and certain damsels are the only species of fish that can avoid the potent poison of a sea anemone. There are several theories about how this is accomplished:

The mucus coating of the fish may be based on sugars rather than proteins. This would mean that anemones fail to recognize the fish as a potential food source and do not fire their sting cells.

The evolution of certain species of clownfish with specific anemone host species and may have helped them acquire an immunity to the nematocysts and toxins of their host anemone.

Clownfish live in small groups inhabiting a single anemone. The group consists of a breeding pair, which cohabit with a few non-reproductive, "pre-pubescent", and smaller male clownfish. When the female dies, the dominant male changes sex and becomes the female. Depending on the species, clownfish can lay hundreds or thousands of eggs.

Clownfish lay eggs on any flat surface close to their host anemones. In the wild, clownfish spawn around the time of the full moon and the male parent guards them until they hatch about 6 to 10 days later, typically 2 hours after dusk. Clownfish are omnivorous - in the wild they eat live food such as algae, plankton, molluscs, and crustacea.