soooo i have 2 clowns (tank bread) so they have no idea bout being able to host things...
Actually they do. It's hardwired. In other words, it's instinctive. It's not a learned trait.
Clownfish in the wild are not taught to look for a suitable host anemone, they just do it when they are ready to leave the planktonic stage. After the eggs hatch, usually just after dusk, the baby clownfish swim towards the surface where they remain drifting with the plankton for 8-12 days until they are ready to come down to the bottom to complete metamorphosis and begin the search for a suitable host. There are no parent clownfish to show them how to do this, they already know.
Think about maroon clownfish (
Premnas biaculeatus) for example. They have only one host anemone in the wild:
Entacmaea quadricolor (BTA). Since they have only one possible host, they have to be born with a strong attraction for that one particular anemone species. It's probably a chemical attraction since they were too undeveloped when they hatched to remember what one looked like (and it was dark).
Most clownfish have at least two or three potential host anemones and
Amphiprion clarkii accepts all ten clownfish-hosting anemones. I guess that means a Clark's clownfish's attraction to any one particular host anemone doesn't have to be all that strong since any one will do.
No one knows for sure how baby clownfish locate exactly the right anemone species, all we know is that they are born with that ability and it never leaves them. If you place a juvenile (or adult) clownfish that you purchased at the store that you know is tank-bred in your aquarium, it will still know which host anemone it's supposed to hook up with. It will usually take its time becoming acquainted first but some, especially maroons, just dive right in if the right host is present.
If the right host anemone is not present, they will often adopt something else as a surrogate host. In fact, even if the right host anemone is present, some of them will sometimes prefer a coral, especially
Goniopora or
Alveopora species, instead of their natural host anemone. And these two corals are the most likely to be damaged by the constant rubbing of a clownfish.
So it's all a big mystery as to exactly how a baby clownfish can find the correct host anemone without parents to teach it but we just know that they usually do. And if they don't do it quickly enough, they will be eaten by something.