Summary

Sea urchins belong to the class Echinoidea, within phylum Echinodermata (Ruppert et al. 2004). They are exclusively benthic animals (Santos & Flammang 2004) and display many adaptations correlated with their benthic lifestyle (Flammang et al. 2005). Temnopleurus alexandri belongs to the Temnopleuridae family, within order Camarodonta. They are found as deep as 73m and inhabit coarse substrates as well as seaweed beds (Miskelly 1968) around Australia, where they feed on various plant matter and loose benthic materials. T. alexandri exhibit a variety of test and spine colours, including shades of green and purple. They display collecting behaviour, covering themselves with various materials available in the water column. They do this using their advanced hydraulic organs, the tube feet (Flammang et al. 2005). These tube feet are involved in a number of other processes, such as locomotion, feeding and sensory perception. Their structure and function is detailed in depth in the Anatomy & Physiology section of this informational webpage, based on extensive literature reviews and lab observations.