Physical Description

Amphimedon Queenslandica is classified within this genus due to its distinctive blue – green colour as a healthy sponge, and encrusting robust growth form (find article). It grows thin to moderately thick crusts over coral rubble, usually accompanied by a large lobate or digitate bulb (Leys & Degnan 2001; Hooper & Van Soest 2006). This characteristic body form can range from several centimetres high and in diameter, to exceeding 20cm in diameter. These bulbs allow this sponge to be relatively robust compared to many other sponges.  On the top of each bulb lies a large oscule (10-20cm) surrounded by a slightly elevated membrane.  The surface is smooth and slightly translucent allowing visibility of the underlying skeletal network to the naked eye.  They have a firm texture, quickly returning to natural state when disturbed, and all sponges are very porous. (Hooper &  Van Soest 2006; Degnan et al. 2010).