Family Trachyphylliidae is a monotypic family of corals popular with marine aquarists. A monotypic family is a family that only contains a single genus, and in the case of Family Trachyphylliidae, that genus is Trachyphyllia. The family and genus name originates from Greek and can be roughly translated as “rough leaf.” Marine aquarists know these corals as open brain corals, folded brain corals, crater corals, and (Pacific) rose corals.
All open brain corals possess a large polyp or polyps with a fleshy mantle. Their skeletons form short valleys with separate walls that are readily identifiable as “brain-like.” Open brain corals are known to expand their mantles up to three times the size of the animal’s skeleton. This makes for a very attractive display in the reef aquarium, especially considering that they fluoresce beautifully under actinic lighting.
Within the genus Trachyphyllia, there are two species commonly seen in the aquarium hobby. They are:
- T. geoffroyi
- T. radiate
The main difference between the two species is that T. geoffroyi is always a soft substrate (e.g. sand or mud) dwelling, free-living coral, while T. radiate is often attached to live rock or another hard substrate. T. geoffroyi is actually a secondary free-living coral, as it begins its life as a polyp attached to a hard substrate but later detaches and establishes itself directly on a soft substrate. Placing T. geoffroyi on live rock can be very detrimental—even lethal—to the animal, which may damage its tissue by way of abrasion as it expands and retracts its mantle. On the other hand, T. radiate may be placed on the rockwork.
The aquarist can tell the difference between the two species usually by looking at the underside of the animal and observing its calcareous skeleton. The skeleton of T. geoffroyi is most often conical, which is useful for establishing itself on soft substrate, while the skeleton of T. radiate is usually flat.
Key Husbandry Points
- Keep in a tropical marine aquarium with stable water parameters.
- Consider dosing calcium, strontium, magnesium, and possibly iodine.
- Keep T. geoffroyi in an aquarium with a soft substrate.
- Offer small meaty pieces of marine flesh that have been soaked in a vitamin supplement such as Selcon at least once a week.
- Only keep open brain coral in aquaria with moderate to high intensity lighting.
- Provide moderate water flow to help the open brain coral keep sediment from settling on its tissue.
- Be cautious with certain species of sand sifting fishes that can prove problematic in that they may deposit sand on the open brain coral, which can eventually lead to tissue death.
- Quarantine all corals before adding them to your system.
Ret Talbot - Ret Talbot joined Suite 101 in December 2007, and he is now the feature writer for saltwater fish—a topic in which he is both ...
