This sub-family of damselfish are commonly called Anemonefish or Clownfish.
Live in close association with on or more of the 10 host species of sea anemones (see: Anemones Hosting Clownfish). Protected from the anemone's stinging cells by their mucus which carries and anemones' chemical signature. This inhibits the stinging cells from firing and is acquired by the larvae during settlement at the anemones base. Anemonefishes are protandrous hermaphrodites, that is all matures as males, then may reverse sex later. The female is the largest most dominant fish of each colony, and her presence inhibits the sex reversal of the males. Feed primarily on zooplankton and filamentous algae. 
- Clownfish and Anemone Compatibility Guide - Reefs.org
- FAQs about the Clownfish Identification - WetWebMedia