Ecology

Most soft corals are susceptible to abrasion and damages done by extreme tidal waves however, these thick and encrusting soft coral species are able to withstand the wave action. Hence, they can be found normally in the coastal waters on crests or rocky shores in wave-exposed environments (Fabricius & Alderslade 2001). They are scarce and rarely be found in a broad range of other reef habitats as the colonies of Cladiella pachyclados tend to secrete mucus therefore requires strong wave action on a daily basis to remove the mucus from the surrounding of the coral (Thiel 1997).

The colonies of Cladiella pachyclados are found attached to boulders or hard substrates on the south side outer-shelf of the Heron Island Reef. The physical environment found here is mainly high visibility water with low particle loads and slight resuspension of sediments. Disturbances by terrestrial run-off are absent however occasional upwelling of nutrient-enriched deeper water occurs here.

The colony tends to attach onto boulders and rocky substrates. It was discovered that there is a variety of invertebrate community living together with the coral. For example, the holothurian (sea cucumber) shown in the picture below. It is hypothesized that this sea cucumber uses the similarity in colour to the coral to camouflage itself by other predators as it burrows among the boulder and coral. The second picture shows a crab living within the damaged tissue of the colony. The last picture shows a sponge living on the boulder.