Photosynthetic gorgonian FAQs

by Owen James

A gorgonian shrimp clings disguised to a branch in this close-up

A gorgonian shrimp clings disguised to a branch in this close-up

(Image by: Nick Hobgood)

The gorgonians bring a totally unique dimension to our reef tanks. They come in many different varieties; with their branched, whip-like or fanned bodies that sway in the current they are unlike any other corals.

Gorgonians are known in the aquarium trade by names such as sea fans, sea whips and sea plumes, which all aptly reflect their appearance.

This article concerns photosynthetic gorgonians – that is, gorgonians that can utilize light as an energy source. Non-photosynthetic gorgonians need lots of food and are much harder to keep healthy in captivity.

Where do gorgonians come from?

Gorgonians are found in reef systems across the world. They are particularly prevalent in the Caribbean, where there is apparently less competition from the soft corals that dominate reefs of the Indo-Pacific.

Gorgonians typically live in shallow tropical waters, though non-photosynthetic gorgonians have been found thousands of feet below sea level and some occur in coldwater. There are more than 500 gorgonian species known to science.

These gorgonians have colonised a submerged bridge:

This video from the Bahamas features abundant gorgonians:

How big do gorgonians grow?

Gorgonian species range from those that grow several feet high to small, encrusting species.

In good conditions the kinds usually kept successfully in aquariums – such as the various Eunicea, Pterogorgia and Muricea species – grow about as tall as your aquarium will allow them to. Their branches range from cocktail stick to pencil-width in thickness.

Just hope yours don’t grow as big as this sea fan!

Can I keep gorgonians?

If you have a fully-fledged reef tank and you obtain a healthy and suitable specimen, yes.

Many different kinds of gorgonians make their way into captivity, so be sure to confirm with your supplier that the gorgonian you buy is photosynthetic and a good candidate for aquarium care.

Many gorgonians ship badly:

  • Don’t buy specimens with any sign of an exposed skeleton, unless you’re an expert
  • Ensure the coral is firmly connected to a base rock
  • Frags created through captive propagation are the best choice for new gorgonian keepers, although the variety is rather limited

All gorgonians require strong water currents – for feeding, and to shed the waxy film which helps protect them against invasion by algae and other small life forms. Their bodies will flex as the water moves back and forth, so ideally use a wavemaker or other device to change the direction of tank currents and to create turbulence.

Some reef keepers are experimenting with tanks providing strong laminar (one-way) flow for non-photosynethetic gorgonians but turbulence is better for the shallow water photosynthetic gorgonians. Put your gorgonian in the most turbulent area of the tank!

Lighting is important, and can be slightly tricky. Gorgonians don’t need the brightest light, which is handy since they grow so tall. But they do require strong lighting: sufficient high-output T5 flourescents or indirect metal halide lighting. If keeping directly under metal halides, your best bet is to start the gorgonian in a darker area of the tank and move it towards the light over a period of days.

Warning: Gorgonians produce sweeper tentacles that will sting other corals. Keep them a safe distance from other tankmates, and consider fragging or cutting back large specimens if you see the scars of aggression on their neighbors.

What do gorgonians eat?

Most gorgonians can capture small food particles in their polyps, and you may see these extended when you feed your fish. A few gorgonian species seem to eat nothing in captivity, though they may absorb nutrition through some other method.

Good lighting and the by-products of feeding the fish is enough to sustain commonly-kept photosynthetic gorgonians. If you want to experiment further, try live zooplankton or frozen Cyclopeeze.

Have gorgonians reproduced in captivity?

Established gorgonians are easily fragged. Simply snip branches off a healthy specimen with scissors, strip away a little of the covering tissue from the base to expose the skeleton, and stick it to a piece of live rock using aquarium epoxy.

Fragmentation mimics the storm damage and reattachment that has allowed gorgonians to spread across the Caribbean.

Learn more

Have you kept gorgonians? Add to our knowledge in the comments below (keep to gorgonian information only, please).

Read the Ultimate Secrets To Saltwater Fish And Invertebrates.

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