No matter how frequently the battle hardened marine aquarists warn newcomers about research, reading and going slow, people new to starting up nano reefs and marine systems still plunk down corals in their tanks as soon as the cycle is completed. Everyone wants an instant reef. In addition, many will not do the research necessary to understand the requirements of the various corals that they put in their tanks. Some corals are nearly indestructible (ricordea sp.) while others close up at a hint of nitrates (sacrophyton elegans).
In order to have your corals do well, one needs to replicate their natural environment as best as possible. This requires increasing your fund of knowledge. Variables to consider include:
In order to have your corals do well, one needs to replicate their natural environment as best as possible. This requires increasing your fund of knowledge. Variables to consider include:
- water movement
- illumination
- reef placement (substrate vs. reef)
- spacing
- feeding requirements
- compatibility
- Mesenterial filaments: These are digestive organs that are extruded thru the coral's oral disc, extending to the neighboring coral and literally digesting it. This leaves a bare area of corallite that can then be colonized by the other coral
- Acrorhagi: Sac-like cells present under the tentacles of Actiniidae. They contain nematocysts that cause local tissue necrosis when contacting other animals
- Sweeper Tentacles: Smaller, thinner tentacles with nematocysts that have developed for aggression and self-defense. They are most commonly found in hard corals but have been discovered in some softies. Corals that are commonly (and injudiciously) placed in marine aquariums include bubble coral (Plerogyra), anchor coral 9Euphyllia), Goniopora and Galaxea, that latter are considered highly aggressive.
- Toxic Compounds: These are most commonly secreted by soft corals and leathers. Two of the most common toxic compounds are terpenoids and sarcophine. These compounds are secreted into the water and assist to deter predators and maintain living space. This is called allelopathy. Corals that commonly secrete these compounds include Sinularia, Tree Corals, and particularly Devil's Hand. When placed close to hard corals, these soft corals can cause stunted growth and even death. As mentioned above, hard corals can have sweeper tentacles. Battle between the two can ensue with extensive damage to both species.
