E. complanata is commonly associated with sandy habitats, hiding beneath intertidal boulders and coral heads of tropical waters. Therefore, local distribution is patchy and confined to habitats that provide adequate shelter and food supply (Barosso et al, 2010).
Heron Island, Queensland, provided an ideal habitat for E. complanata, along the intertidal zone bordering the Southern margin of the Island (figure 1). This area was identified as an ideal habitat for the fireworm and observations confirmed the species presence. Multiple fireworms were often observed sheltering beneath the same boulder. One such boulder exhibited 7 small E. complanata co-existing beneath the same 50cm2 Boulder. No such aggregations of large individuals were observed. They were often found living in association with Limidae bivalves. Little is known of the feeding, behavioral or social ramifications of fireworms sharing a particular habitat.

Figure 1. Ideal E. complanata habitat. Heron Island, Queensland |