Open Brain Corals (Trachyphyllia): Care and WYSIWYG Brains for Sale

An open brain coral is a single free-living animal that sits on the sand and inflates into a folded, fleshy dome two or three times the size of its skeleton. Trachyphyllia geoffroyi is the classic hourglass-shaped one; the round, ruffled “Wellsophyllia” of the trade is a form of the same animal, and our listings carry both names so you know exactly what you are getting. Reds, pinks and metallic greens in one polyp — under blue light an open brain reads from across the room.

Care at a glance

The placement rule is the whole game. An open brain inflates far beyond its skeleton, and flesh pressed against rock tears when the animal deflates at night. Give it open sand and it will do the rest. Feed it in the evening as the feeder tentacles come up, and a healthy trachy visibly grows — it is one of the most rewarding LPS to actually watch.

Like a scoly, an open brain is one polyp, one animal — it will not spread into a colony, so the WYSIWYG photo is the entire purchase decision. The photo is the exact animal.

These belong on the sand, not glued to rock

The most common way people damage an open brain is to treat it like every other LPS and epoxy it onto the rockwork. In the wild these sit on soft substrate. The skeleton is cone-shaped and designed to rest in sand, and the animal inflates well beyond the footprint of that skeleton.

Put it on the sand bed, on the flat, with nothing sharp under it and nothing within reach of the inflated edge. If it is going on rock at all, it needs a level shelf it can sit in rather than a vertical face it has to grip.

One thing that follows from that shape: an open brain that has fallen or been dropped can tear its tissue on its own skeleton edge, and that tear is where infection starts. Handle by the skeleton underneath, never by the flesh.

Buy the skeleton, not the balloon

A fully inflated open brain can be two or three times the size of the animal underneath. That is why photos of these are so misleading between sellers: one shop shoots it puffed up at midday, another shoots the same size animal deflated, and the buyer thinks one is much bigger.

Ask for the skeleton measurement, not the tissue measurement. That is the number that does not change with the hour of the day, and it is the honest way to compare two animals at two prices.

What to check in the photo before you buy

Because the whole animal is visible in one photo, a good WYSIWYG listing lets you inspect the same things we inspect when a piece comes into the shop. Go down this list on any open brain you are considering, ours included.

What a healthy one looks like when it arrives

• Deflated is normal. Every open brain ships shrunken. A piece that arrives tight to its skeleton is not a damaged piece. Give it a day or two on the sand under normal light and it inflates.
• The mouth is closed. Check this first. A closed mouth on a deflated coral means it is stressed but fine. A gaping mouth is the sign to photograph and report.
• No fresh white. Compare the rim of the skeleton to the listing photo. If the tissue coverage matches, the animal shipped well.
• Feeding response within a week. Once it has inflated, a small piece of mysis or a pellet dropped on the mantle in the evening should be drawn slowly toward the mouth. Slowly is the word: an open brain can take several minutes to take a single brine shrimp.

If something is wrong, photograph the animal inside the unopened bag within four hours of the UPS delivery scan. That is what our Live Arrival Guarantee needs, and it is the same for every livestock order.

What goes wrong, and why

None of that is a treatment claim. An open brain with intact tissue and a closed mouth usually recovers on its own once the cause is removed; one that has lost tissue around the mouth often does not. We would rather you know that before you buy than after.

Open brain, meat coral, scoly: how they differ

Three big single-polyp LPS corals get mixed up in listings. Trachyphyllia has a folded, brain-like mantle over a cone or disc skeleton and lives on sand. Acanthophyllia is a smoother, more inflated dome over a heavy skeleton, often with a translucent look to the mantle. Scolymia (many now sold as Homophyllia) is flatter, disc-shaped, and usually attached to rock. All three want the same low-flow, moderate-light, well-fed life; they are just different animals, and they are priced differently. For what the WYSIWYG label actually promises, read what is a WYSIWYG coral.

Light, flow and the deflation people panic about

Low to moderate light and gentle flow. These come off soft-bottom habitats, not the reef crest, and putting one under a bright spot with a powerhead on it produces a coral that never fully opens and slowly recedes at the edge.

They also deflate at night, sometimes dramatically, and put out feeder tentacles. A brain that looks half its daytime size at ten at night is feeding, not dying. The one to worry about is the one that stays deflated through the middle of the day, or that shows bare skeleton anywhere around the rim. Ours are photographed in our Key West systems, and on a WYSIWYG listing the photo is the exact animal that ships.

Open brains in stock now

One thing to know before you order: the $10 Box & Handling Fee is charged by the box, not by the coral, and UPS Next Day Air is one flat shipping charge per order. A box holds several corals for the same $10 Box & Handling Fee and the same overnight ride, Florida orders under 6 lb ship UPS Next Day Air for a flat $30, and livestock orders of $349 or more ship free. If this page puts one coral on your list, it is worth seeing what else belongs in the box — start with corals under $100 or the newest WYSIWYG pieces.

Our stony corals are either aquacultured at the shop in Key West under Florida Aquaculture Certificate #AQ0254072 or conditioned in our Key West systems before they ship, and the photo on a WYSIWYG listing is the exact animal that ships. Corals ship UPS Next Day Air every Tuesday and Wednesday. If you are ever in Key West, come see the raceways.