Ecology

Habitat

Echinometra mathaei are found in a wide range of microhabitats, throughout shallow tropical waters. In high energy environments such as on the reef crest, they are known to excavate burrows in which they shelter from the elements, while in lower energy environments, they are found in crevices, on solid rock or coral formations, or amongst patches of algae attached to solid substrata (Neill, 1988). On Heron Island, these urchins are found on both the top of the reef crest, and on the backside of the reef crest in the lagoon. On top of the reef crest, these urchins are found underneath large coral boulders and rubble, often hidden within the boulder in burrows or cracks. On the backside of the reef crest, they are found on solid coral formations, hiding in natural crevices or burrows, or on top of the substrate as they feed when the sun goes down.

Associations

Ectoparasitism by several different copepod species is known to occur on E.mathaei around the world (Huys, 1988). These parasites are found on the surface of the body, amongst the spines, feeding on the urchin. A species of gastropod is also known to parasitise these urchins, moving freely across the body, causing lesions which may lead to mortality from infection (Vaïtilingonet al., 2004). While these parasites have been found in a number of locations around the world, there have been no studies on the occurrence of these parasites on E.mathaei at Heron Island.






Figure 1. E.mathaei grazing on coral substrate, behind the reef crest.