Clownfish are also called anemonefish thanks to their symbiotic behavior with those animals. After appearance in "Finding Nemo" their popularity rapidly increased. They are common fish in saltwater aquariums, primarily because of their recognizability and appeal but also due to relatively low requirements for keeping.
There are 30 species of clownfish. Twenty-nine belong to the Amphiprion genus and one to Premnas.
They often inhabit a symbiotical anemone which provides them with protection while clownfish feed it with feces and lure larger fish into its poisoning tentacles.
Clownfish also give protection to anemone fending off its predators and possible parasites.
Most clownfish species have orange-colored bodies with one or more white bands.
Bands usually are outlined with a black line.
The most popular clownfish species is Amphiprion ocellaris, which is eagerly kept in reef tanks throughout the entire world.
It might be the most popular saltwater fish. Here is some detailed information on Ocellaris anemonefish:
they can reach up to 11 cm (4,3 in) body length,
they live in eastern Indian Ocean and western Pacific, sometimes can be found near coastline of Japan and Australia,
famous Nemo was exactly this species, Amphiprion Ocellaris
Clownfish are omnivores.
They usually eat leftovers from anemone host but can also feed on zooplankton, algae, copepods and tunicate larvae. They sometimes take a bite of hosting anemone tentacle.
They are very hierarchical animals.
On the top of hierarchy, there is the most aggressive and largest female.
They are monogamic.
A clownfish colony is made of a single female, reproductive male and supporting juvenile males. Only a reproductive male takes part in the breeding process.
Like most fish, clownfish reproduce externally.
Male prepares a flat rock for breeding. A female lays 600 to 1500 eggs, depending on her size.
Male is taking care of nest and hatchlings.
After the copulation he is responsible for taking care of the nest. He removes dead eggs with his mouth and uses pectoral fins to circulate water to provide it fresh and oxygen abundant.
Young clownfish hatch in 6 to 10 days after laying eggs.
This usually occurs at night, 2 hours after dusk.
Clownfish are most often traded marine fish.
Most of the global trade comes from the wild, but things are changing over time. Clownfish are easy breading in captivity so from year to year less of them are captured from the oceans.
The average lifespan of clownfish is about 10 to 13 years in the wild.
But there are species living substantially longer like Amphiprion percula, which can live in captivity up to 30 years.
All clownfish are born males.
They can become a female in adulthood. It happens for example if a dominant female is killed.
When clownfish lacks anemone, it can occupy soft coral or large polyp stony coral.
Sometimes they even prefer those corals over anemones. This happened in our editorial reef tank when Amphiprion moved to Pleogyra coral, leaving Entacmaea quadricolor anemone alone. It stays away for over a year, and I'm sure it won't go back anytime soon.