Clownfish: Surviving Nemo

Clownfish: Surviving Nemo.

The Pixar movie, “Finding Nemo,” in 2003, by Andrew Stanton, won the Oscar and introduced the Clownfish to the hearts of people from all ages, but especially kids who immediately wanted one or more in an aquarium. Clownfish were, even then, a recognised salt-water aquarium fish and had been bred in captivity since about 1970. More on this later*.

There are 29 species of Amphiprioninae Percula - clown fish, and perhaps more as yet unknown. They are reef dwellers, found in tropical waters from Africa to Polynesia; Japan to Australia, with the largest concentration of species found in New Guinea: the last member of the family to be named was found recently in Fijian waters, the Amphiprion Barbari. They are remarkable for their bold colouring, purpley-brown to orange, red and yellow, the colours often separated by bands of white or black; these adornments, of course, reminded early marine biologists of how a clown paints his face, hence their name.

Their life is as interesting as their colouration is arresting. Clownfish all have a symbiotic relationship with venomous anemonefish in the wild: commonly called sea-anemones. The clowns spend their whole lives inside the protective tentacles of their host, or in water close by where they can beat a hasty retreat into the anemone’s protection if threatened, especially by their arch enemy, the Moray Eel. In return, the clown provides its own faecal matter as food for the anemone; circulates water around the creature, and also protects the anemone from predators such as the Butterfly Fish.

It is not entirely clear to biologists why the clownfish doesn’t get stung by the anemone. They theorize that the clown has a film of mucus all over its body which fools the anemone into not firing its Nematocysts. A large anemone may have as many as 30 clownfish or varying sizes living around and in it. Clownfish are all born males but can use Sequential Hemaphroditism to change sex as circumstances direct. They are one of the very few which can change from males to females, as well as the reverse.

In the wild, mainly due to predation, the clowns have a life span of about 7 to 10 years; they have reached more than 20 years in captivity. Omnivorous, clownfish feed on minute organisms around their host, such as plankton and algae. They grow, depending on species, from 3 to 7 inches.

*Since the wonderful movie, clownfish have become one of the most popular aquarium species. This has caused a problem on many reefs: as the fish were taken in their thousands, the anemones soon died or were predated upon, contributing, in some cases, to the death of the reef itself. Breeders and stockists have done well in catching up, and tank-bred fish now make up around 80% of those acquired for aquariums.

Some species are better suited than others to aquarium life with other denizens. The Maroon Clownfish, for example, may be aggressive to other aquarium dwellers, whereas, the False Percula, for one, is usually peaceful. In many ways, it is better to only buy artificially raised clownfish. Not only do you then eventually ensure the cessation of the cruelty of removing them from the wild and protecting the anemone and the reef environment, wild fish may soon die due to the stress of catching and shipping. With those raised in captivity, you may have to artificially “teach” the clowns to inhabit and live with any anemone you have introduced. They will seek shelter, but it may be a rock or coral in your tank where you might hardly see them at all. Wild fish will, of course, need to have anemones in place and these are also special species: The Bubble Tip is perhaps the most common, but there are more which different clownfish use and they may or may not easily adapt..

For me, these gaily coloured and fascinating little reef dwellers should be enjoyed in situ, or perhaps in a large commercial aquarium which as nearly imitates their natural life as possible.

If you do decide to keep them, remember that they live in family groups in the wild and should never be kept as just one individual fish…a breeding pair would be the minimum I would consider - and don’t forget, any two clowns can be a breeding pair as they adjust their sex to suit conditions: Might pay to wait awhile before you name them!