As a Moorish Idol becomes older, the fin
streamer of this fish becomes shorter. Although not always the
case, adult male Moorish Idols tend to fight with one another.
When they are younger they may travel in schools but as they
become older they tend not to.
Moorish Idols are incredibly difficult
to care for in captivity. While in captivity they almost never
live out their full lifespan. One of the major reasons for this
is their incredibly complex diet in the wild that is almost
impossible to mimic in captivity. Basically, Moorish Idols are
best left in their natural habitat despite the tempation to
bring them into captivity.