There are always curve balls when attempting to pair clownfish. Here are some potential problems and solutions:
- Make sure that your male is actually a male. Sometimes, if the clownfish is left alone for a period of time, it may become a female. Once it's a female, it remains a female (unlike some other species of fish that can change sex, once a clownfish has become a female it cannot change back). Since your ocellaris is already over a year old, it might've transitioned to a female. One way to ensure that your fish is a male is to remove the male from an established pair, or find a juvenile. Of course, the drawback is that you may have to wait (possibly a couple of years!) for the juvenile to become old enough to breed.
- Females, like many other animal species (such as **** sapiens) are picky--and unpredictable! I have a female percula that killed two males, without warning. They just made her mad and she ended it. Try to introduce the male slowly--using a clear plastic container that allows the clownfish to see each other will help. If you can re-arrange the rockscape, that should help as well, since it will reduce any defensive tendencies with regards to territory. This includes moving the host anemone, just temporarily, if you have one.
- Make sure that both fish are well fed. This will make them a bit more sluggish and less prone to being "grumpy."
- Cross your fingers. Pray (if you're into that sort of thing). Anything will help.
Good luck and keep us posted!