Seafans, more specifically called gorgonians, are the branching corals that form finger or flat fan looking shapes. They are comprised of flexible branching skeleton called gorgonin. The soft tissue that covers the branches is called coenenchyme, and comes in a variety of red, orange, yellow, purple and brown colors. Within this tissue reside the polyps, which are colonial in nature, meaning as one feeds it benefits the entire colony.

Gorgonians require heavy water flow and preferably a flow that oscillates back and forth, or at the least a chaotic flow. They will not tolerate free floating algae, or any hair algae, in the aquarium as this eventually becomes caught up in the web of the seafan and results in smothering it.

Seafans will require feeding. This can be done in a number of ways. One way is to gently stir up the sand at the bottom of the tank. This will result in suspending a number of small particles, bacteria's, and small bits of organic compounds into the water. Another method is the addition of 'green water' ( phytoplankton )or freshly hatched brine shrimp ( zooplankton ) into the aquarium. One can also use tweezers or a pipette to introduce small pieces of mysis shrimp directly onto the polyps themselves.

Most of the gorgonians being imported come from either the Pacific or the Caribbean. It is best to select ones that are openly branched as opposed to the tightly interwoven ones.

Some gorgonians are photosynthetic ( light requiring ) and some are non photosynthetic ( not light requiring ). One should consult literature as to their specific needs. It is safe to say that all gorgonians prefer strong, oscillation or chaotic, water movement.