Ecology

Ecosystem Engineers

Echinoids feed mainly on algae, but are also known to consume plant and animal matter (Ruppert et al. 2004). Their ability to do this has earned them their ecosystem engineer label, as they can dramatically change the areas in which they feed. Urchins can be classified into grazers and browsers; where browsers bite off plant material and eat loose bottom material and grazers actively scrape matter off substratum. Intense grazing from urchins can result in large-scale barren grounds, which can impact on the whole structure of a community (Harrold & Reed 1985). As T. alexandri is a browsing species it can be assumed that it isn’t as great a threat to the ecosystem as a grazing species but would play an important role in controlling algae in the systems it inhabits.