I always like to see pairs of fish, and sometimes it works out, but sometimes not.
Paired fish in my care that seem OK together:
Flame wrasses
Bellus angels (occasional spawn display but mostly they just bicker)
blue mandarins (reasonably regular spawning)
ocellaris clowns (regular spawning)
chromis
pyramid butterflies
Pairs that were more "just 2 fish of the same kind" and ended up "not OK" together:
- Double saddleback butterflies - they schooled together all the time at first, after 2 years they started showing aggression to each other. They started getting ich pretty badly, eventually one died, and shortly afterwards the ich cleared in the remaining one.
- Doliatus rabbitfish - always wanted two, they seemed to tolerate each other but that was it.
- Virgatus rabbitfish - same story, had a pair, they hung out together but never witnessed anything like spawning.
Also had a pair of flame angels for a while in a tank a while back. Unfortunately lost both in a prolonged power failure. I'm pretty sure they had paired up too.
