INTRODUCTION TO ACROPORA CORALS FOR THE BEGINNER REEF AQUARIUM HOBBYIST

  A crash course in keeping Acropora Corals
 
Acropora corals are highly adaptive, opportunistic and fast growing, which has made them a very popular species in reef aquarium hobby. Acropora can be found in a variety of grow forms ranging from plates to staghorns and a variety of colors. With the popularity and variety of this coral an entire website could be dedicated to their selection and husbandry. However, this guide will introduce the various varieties of Acropora and will cover their scientific background and information related to Acropora within the context of the reef aquarium hobby environment.
 

 
  Scientific Information
 
Genus Acropora (ak-roh-pohr-ah) is part of the largest family and most important contributor to coral reef formations in the world. The two primary genera Acropora and Montipora together account for almost one-third of all hermatypic or reef-building coral species. While found in both the pacific and atlantic oceans, Acropora is far more dominantly found in the Pacific ocean as there are only 3 known species of Acropora in the Atlantic. Acropora contain specialized axial corallite, which do not contain zooxanthellae, but allow for a very rapid growth rate, as they are fed by other areas of the colony. This allows for the genus to have a advantage over other corals in that they can outgrow them and rapidly colonize the reef. These fast growing Acropora branches can be identified by their light-colored tips, which are almost white or brightly hued.
 

 
  About Acropora Corals
 
There are 13 to 15 basic growth forms of Acropora that vary according to size and shape of the branches, the position of the brances, the number of corallite septa and the nature of the coenosteum. The most commonly available aquarium species tend to fall into the following growth forms: branching, bushy, cluster, finger, bottlebrush and tabular. In the aquarium hobby , species are generally sold by form and color as oppossed to the species i.e. purple staghorn or pink bottlebrush. This is understandable, but can make it difficult in providing a species designation, which is then left upto the aquarist.
 
Acropora are highly diverse and adaptable, which makes figuring out the best aquarium conditions difficult. Specimens have been collected in a multitude of areas including areas of strong water current and intense lighting to deep water areas and calm lagoons. Pretty much anywhere coral reefs can be found, Acropora can also be found there thriving. Discussed in the next section, growth forms and not species are probably the better indicator of the natural location of the coral. Coloration of Acropora is even more diverse than the growth forms, with almost every hue of the rainbow possible.
 

 
  Acropora Corals in the Home Reef Aquarium
 
Acropora in the wild are highly adaptable and can exist in a variety of locations including: calm lagoons, pounding reef crests and even reef flats where they can be out of water for periods of time. They tolerate huge differences in light intensity, water movement and even salinity, thus one would think that they would extremely easy to keep in the reef aquarium, but nothing could be further from the truth. In fact they are very demanding of their conditions when housed in captivity. However, once they are acclimated to aquarium life, and if kept with stable water conditions, they will also thrive in the reef aquarium.
 
Generally speaking, Acropora species with thick branches are normally more difficult to keep than those with thin branches. This is most likely because of the inability of reef aquarists to provide enough water flow that the thick branched species need to thrive, thus making these species more prone initially to problems. Brown specimens, bottlebrush and thin branched species tend to be more tolerant of the lower water flow and light level conditions. Tabletop species are among the most difficult Acropora species to keep in the home reef aquarium, with staghorn specimens being somewhere in the middle.
 

 
Captive-bred or frag specimens seem to be generally healthier and easier to care for than wild specimens. Nonetheless, all Acropora specimens seem to prefer strong, random or mixing type water current with intense lighting and high levels of calcium and strontium to promote maximum growth and health. Water quality should also be excellent and very stable, thus Acropora do much better in established reef aquariums where water parameters are generally more stable.
 

 
  In conclusion
 
Acropora need to be acclimated carefully to their new surroundings so that they are not shocked by light, water parameter changes or other stresses. They should also be located in their final position as quickly as possibly to avoid stress or unfulfilled metabolic needs. Typical stressors include: low light, low water current and frequent movement from different positions in the aquarium. They do not tolerate sudden changes in aquarium conditions, especially water temperature and will fade in color, recede in growth or even die if proper water conditions are not maintained. While frag or captive-bred species do best, they often require about 6 months to regain full normal growth rates.
 
Acropora are also susceptible to most known coral diseases including: white-band disease, black-band disease, recession, etc. While Acropora are a demanding species to keep in captivity, it is possible to keep them successfully and can be an extremely rewarding coral to keep and raise. Hopefully the information in this article along with the experience obtained from keeping corals in the reef aquarium will help increase the likelyhood that these corals can not only be kept successfully in the reef aquarium, but also thrive as well.