Weird Fact: Clownfish change from male to female
The ocean floor is full of weird and wonderful creatures, perhaps none more famous than the clownfish. Thanks to the spotlight that Disney’s Finding Nemo put on this little guy, many people are taking a closer look…and this unique fish deserves all the attention he gets.
What are Clownfish?
The familiar orange and white clownfish is only one of the twenty-eight species of amphiprion, also known as Anemone Fish due to their symbiotic relationship with sea anemone. Clownfish size ranges from 10 to 18 inches at full maturity and they vary in color, including shades of pink, red, black and maroon.
The orange and white striped ocellaris clownfish may be the most recognizable type of clownfish but all amphiprion are striking, a feature which appears to serve a purpose – attracting dinner for the sea anemone and cleaning up on the leftovers.
How do clownfish change sexes?
Clownfish are sequential hermaphrodites, which means that their life cycle is a little complicated. All types of clownfish develop first as males and mature into females only when they reach the top of the group hierarchy. Hermaphroditism is not rare in fish and marine life, but in 75% of sequential hermaphrodites, the organism begins female and becomes male upon maturity…not so with our friend, the clownfish.
There is a single breeding pair and a number of smaller males within any group of clownfish. Should the female die, the most aggressive male will gain weight, change to female and assume her role. The next largest of the younger fish will then take his place as the breeding male in the group.
Dr Justin Rhodes, Associate Professor of Psychology from the University of Illinois studies Clownfish. He does a fantastic job of explaining what happens when they change from male to female.
Where do clown fish live?
Anemone Fish live in shallow seas and reefs. They thrive in warm water environments like the Indian and Pacific oceans as well as the Great Barrier Reef. Their habitat is easy to recognize because wherever sea anemone are, clownfish will be close by. One of the most interesting facts about the clownfish, beyond its gender-bending, is the relationship it has with the sea anemone, a stationary omnivorous sea creature with poisonous tentacles.
There are various theories as to how the clownfish and anemone can live in such close proximity, with clownfish making a home where other fish go to die. Some scientists believe that a mucus which covers the skin of clownfish prevents the poison from penetrating. However, a peculiar behavior has been noted in clownfish that may explain their immunity. When approaching an anemone for the first time, clownfish have been observed brushing up against the tentacles with its body again and again. It is possible that this little dance allows them to build up immunity to the anemone’s toxins.
Once the clownfish has taken up residence in the anemone’s deadly tentacles, a kind of mutualism takes place. These fiercely territorial fish protect the anemone from possible prey but also attract other small fish which the anemone can sting and then eat. Clownfish will eat plankton, crustaceans and algae but their diet primarily consists of the sea anemone’s leftovers. Should the anemone lose the use of a tentacle, the clownfish will eat that too.
Are clown fish endangered?
Currently, Clownfish are considered a threatened species. However, in 2012 a petition was filed to request that they be added to the endangered species list. The threats against them include; global climate change, ocean acidification (pollution) and the marine ornamental trade. A whopping 43% of global aquarium trade is in clownfish and 75% of those fish are captured in the wild. For this reason, it may be best to leave Nemo where he lives among the coral reefs and sea anemone and love him from afar.
Copyright © Mark Beselt