different size clown fish Question

Today I was at the LFS and bought my first two fish for my aquarium. I got two percula clown fish. The man told me to get one small one and one bigger one. Why is this?

 

its so they can pair up; if there almost the same size they fight to the death

 

The larger fish if not alrealy a female will become one. If already a female she will kill any other females. A smaller clownfish is most likely a sexually immature male.

 

Not quite 100% correct. Clown are born as hermaphradites with the possibility of becoming either male or female. As they grow and mature, they will pair off with the larger one becoming the female and the smaller one the male. However, during the process of pairing off, the clowns may fight, especially if more similar in size. This may lead to the death of one of the fish, but usually won't. He suggested getting two different sized ones to aid in the pairing off process. Do keep in mind that it's not guaranteed that the clowns will pair off. Good luck with them.

 

"Clownfish live in pairs inhabiting a single anemone. When the female dies, the dominant male changes sex and becomes the female.[2] This life history strategy is known as sequential hermaphroditism. Because all clownfish are all born as males, they are protandrous hermaphrodites (pro=first; androus=male).[3] On the top of the hierarchy is the reproducing female followed by the mating male. Below them are a bunch of non-mating males. But, if the female dies, the whole hierarchy gets disrupted. The predominant male then morphs into a female and chooses a partner from the various non-mating males. The largest fish in the group is a female and the second biggest is a male. All the other clownfish are neuter, which means they have not fully developed functioning sex organs for either gender. If the female should die, the male will change sex, while the biggest neuter clownfish will develop functioning male sex organs to replace the male" Wikipedia

Marine Ornamental Fish & Invert Breeders Association • View topic - Clownfishes Breeding/Spawning Overview - Amphiprioninae

There will always be debate regarding the true meaning of protandrous hermaphordites, but for the purpose general discription juvinile clownfish are sexually immature males that may become either sexually mature males or the dominate female. Once a clownfish becomes a female it can not then become a male, except noted in only a few rare instances. The male always has the ability to become a female though.

 

Ahhh I see now. Thanks for explaining.