The corallites within a coral colony may be arranged in a variety of ways. Quickly identifying the predominant arrangement within the colony you are trying to identify, will provide you with a rapid way to narrow down your search.
Note use of the word ‘predominant’ in this sentence, sometimes a coral colony may exhibit more than one type of corallite arrangement. It is important to understand when looking at a coral colony that specific characteristics may not be repeated across the whole colony surface; make sure you scan the entire colony and then concentrate your efforts on the mid flanks of the coral. Why? Because often at the edges of the colony or on the apex, the corallites are affected by stressors such as competition from neighbouring corals, or exposure to high light levels. These stressors can modify corallite appearance, making identification of predominant characteristics difficult. For more in-depth information on the key steps to examining a coral colony have a read of the Coral Identification article.
(Photo of coral colony with mid flanks highlighted)
NOTE: The following slide show cycles through all Key Terms in this section. You can change to showing a different image/key term by using the arrows or clicking on a specific thumbnail. You can pause the slide show by resting your mouse cursor on the main image. To go to in-depth information and more images for key terms click on the yellow links in the captions
- links inside these captions for more info.
Hover over the main image to pause slideshow." title="Entry5" width='170' height='135' />
- wall is a skeletal structure surrounding and defining the corallite." title="Acropora article Coral Finder pages" width='170' height='135' />
- distinct walls to their corallites. Presence, absence and type of wall is important for defining coral genera (singular genus)." title="Slide3-2" width='170' height='135' />
- absent or indistinct walls." title="Slide3-3" width='170' height='135' />
- valleys and ridges. In this case the ridge is also a corallite wall." title="CFT" width='170' height='135' />
- skeletal ridges - the genus Pavona." title="Slide5-6" width='170' height='135' />
- separated walls they are termed plocoid - clockwise from top left: Favia, Favia, Turbinaria & Cyphastrea." title="Slide5-7" width='170' height='135' />
- common wall they are cerioid." title="Slide5-8" width='170' height='135' />
- common walls - cerioid - clockwise from top left: Acanthastrea, Goniastrea, Leptastrea & Coeloseris." title="Slide5-9" width='170' height='135' />
- phaceloid. The genus Lobophyllia may appear to be plocoid but is in fact phaceloid as this broken colony reveals." title="Slide5-10" width='170' height='135' />
- common walls that meander across the colony surface are termed meandroid - clockwise from top left: 2 species of Platygyra, Leptoria, Platygyra & Symphyllia." title="Slide5-11" width='170' height='135' />
- separate walls of this flabello-meandroid Euphyllia are often hidden completely by its tentacles." title="Slide5-12" width='170' height='135' />
- meandroid and phaceloid colony side by side. The size and scale of growth forms may vary but the principles of corallite arrangement remain the same. Experience underwater is key." title="Lizard March 2009 (c) Russell Kelley IPCF" width='170' height='135' />
- Veron, J. E. N. (2000). Corals of the World. Melbourne: Australian Institute of Marine Science.