You will not see the skeleton. This coral keeps its polyps out around the clock, and they are long enough and packed closely enough that the colony reads as a field of soft fingers rather than as stone. Put a hand near it and the whole surface withdraws at once, and what is left underneath is a startlingly light, porous skeleton with almost nothing solid to it.
Count the tentacles and you have named the genus. Twelve, in a neat ring around a flat mouth disc, means Alveopora. Twenty-four, on a longer stalk, means Goniopora, which grows alongside it and is mistaken for it constantly. Nothing else on the reef looks like either.
The porous skeleton is the trade-off that shapes the animal. It builds cheaply and quickly for the weight, so these corals do well on soft, silty, shaded ground where the heavy reef-builders struggle, and badly in surf, where a colony can simply break apart.
The polyps carry symbiotic algae like most corals here and get the bulk of their food from them, catching plankton on the side. In this colony the tentacle crowns are violet against a cream body, which is a color form: the same species elsewhere in its range is the green the name refers to.
- surface completely hidden under soft polyp columns, extended day and night
- each polyp a pale fleshy tube ending in a crown of twelve short tentacles
- tentacle crowns violet here, though the species runs green to cream elsewhere
- colonies rounded, lobed or columnar
- colonies up to about 50 cm
Why it's threatened
Threat classification from the IUCN Red List.







