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Clownfish - Wikipedia, the free encyclopedia
Clownfish are protandrous hermaphrodites, meaning they are hatched as sexually immature fry. Based on signals from their environment and being physically mature (12–24 months) they will either remain sexually immature, change into a male or change into a male then female. A group of clownfish is always built into a hierarchy of this type, with the female (the largest and most aggressive) at the top. The change from juvenile to male, and male to female is irreversible. If the female should die or be removed from the group, the most dominant male then changes into a female, and the rest of the males move up a rank on the hierarchy.
In home aquaria, a juvenile only several months old can make the change from juvenile to male to female in as little as a month. Because of this, pairing clownfish can be a tricky proposition, as most hobbyists tend to select the largest and most dominant specimen (presumably a female) to mate with their own female. Usually two females will tend to fight regularly, and frequently lock jaws (some hobbyists describe it as kissing). In a successful pair, the male will exhibit submissive behaviour. Usually, this behaviour entails the more aggressive female darting at the male, and the male turning sideways and quivering.
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