obligate or required: ie. and obligatory cleaner fish relies entirely on this feeding mode to obtain nutrients (compared to facultative).

A marking that resembles an eye, eye-like colored spot; an eyespot.

Octocorals have eight tentacles on each polyp. There are many different forms which may be soft, leathery, or even those producing hard skeletons.

Animals who eat both meat and vegetables like marine angelfish.

Producing eggs which are fertilized, develop and hatch outside the body.

Producing eggs (usually with yolk) that are fertilized internally. Hatching may occur internally or external to the mother.