Mini reef aquarium guide. Reef aquarium setup for large reef tanks, Nano reef tanks, Pico reef or MIcro reef aquariums with reef tank lighting, filtration, choosing coral reef animals, and problem solving!
The California Hydrocoral is found in cool waters ranging from 42.8 to 55˚F (6 to 13˚C), which means a chiller is a must! The tank should be 100 gallons or more and at least a year old. This corals is difficult to almost impossible to keep alive long term due to the copious amounts of plankton it needs to live. This level of feeding pollutes closed systems. Some have tried skimmerless, algae-scrubbers, Jaubert or the Monaco systems with limited success. Best left in the wild.
The Fire Coral, Millepora alcicornis has earned the name "FIRE" for good reason! It is strong enough to put some people into anaphylactic shock, however most of the time it is a bad sting. The positive thing is that they grow so slow, less than 1" per year, that they can be kept in a nano tank, without the risk of over growing everything so fast. They also will hold their own and other corals will generally stay away from them!
The Fire Coral, Millepora alcicornis, while immune to the Crown of Thorns can succumb to predatory polychaetes and nudibranchs from the Phyllidia genus. Many critters like this crab will find safety in it's branches. Hawkfish, who do not have any tissue on their pelvic fins will perch between the branches and will not be stung as they enjoy the protection of the Fire Coral.
The well-known hydrocorals include the Fire Corals in the Milleporidae family and the Lace Corals in the Stylasteridae family. They are Cnidarians just like the stony corals, but are in the class Hydrozoa.
When diving, snorkeling, or keeping Fire Corals in the aquarium you want to be very careful. The Millepora genus has a potent sting. It may be just a mild sting for some people, but can cause anaphylactic shock in others. Needless to say, wear gloves when you are handling or anywhere near the coral. Don't be dissuaded from keeping them because of their sting, since they are hardy and easy to propagate, just be careful and wear gloves.
Class Hydrozoa There are many animals in the class Hydrozoa, but only a few hydrocorals like the Fire Corals and Lace Corals are found in the aquatic industry, along with some small hydroid polyps. These small polyps can inadvertently show up as aufwuchs on invertebrates and plants, but are short lived in the aquarium.
Hydrocorals Hydrocorals are not true stony corals, they are actually more like a very hard "soft" coral. Yet the Fire Corals are very similar in appearance and habitat to stony corals, and they are also hermatypic. This means they contribute to reef building, creating a hard skeleton from calcium absorbed from the water. The Lace Corals will also produce an aragonite and/or calcite skeleton but are mostly small, "lacy", and very delicate.
Besides the Fire Corals and Lace Corals, there are some other well-known and familiar hydrozoans.
Hydra The Hydra, introduced to high school students in their biology class, is a small solitary freshwater hydrozoan polyp. But it may not be the best example of this class since it does not incorporate all the complexities this animal group possesses.
Jellyfish Jellyfish are also related to the hydrocorals, with some genera included in the class Hydrozoa.
Floating Hydrozoans Some other familiar colonial hydrozoans include the so-called Portuguese man-o' war from the Physalia genera, and the Blue ButtonPorpita porpita. These animals can sometimes be found washed up on the beach and can be mistaken for jellyfish, but a jellyfish is just a single individual while these hydrozoans are made up of multiple individuals.