Although long relegated to a second tier of appreciation, in recent years Zoanthids experienced a surge of popularity which remains fanatical among many marine aquarists. "Zoas" are very hardy and they are one of the first coral additions to a new or developing reef aquarium.

Zoanthids resemble a mat of flat circular polyps with short tentacles at the perimeter. The flat oral disc is smooth and it usually obscures the commonly short supporting stalk. Depending on the species, the stalks may join to form a common encrusting base. Zoanthids occur in every imaginable color with contrasting mouths and tentacles. Zoanthid tentacles are commonly called 'skirts'.

Zoanthids are very hardy animals. They often hitch-hike on live rock and they are often shipped simply wrapped in wet newspaper. They thrive in nearly all conditions but they will look and grow their best when provided with intermediate to strong water flow and intermediate to strong light intensity. Larger Palythoa polyps will readily catch food but smaller Zoanthus polyps show a weak feeding response.

Zoanthids reproduce quite readily by encrusting nearby substrates. Some aquarists like to physically remove the encrusting mats while others find it easier to break up the encrusted substrate. Slightly elevated nutrient levels tend to encourage growth rates. Zoas are very toxic and extreme caution should be used when handling them.