Description

 Tethya aurantium is a spherical sponge up to 10 cm in diameter. It has the appearance of a small orange and may have rooting processes. The surface is 'warty' (tuberculate). The 'warts' (tubercles) are separated by contractile pore-bearing grooves. Sometimes buds are present, found on short stalks on top of these tubercles. When contracted, Tethya aurantium can appear smooth and evenly marked by striations. The striations can expand into grooves or channels, leaving 'islands of tissue'. Between these 'islands' the profile can be rounded or flat. There is usually one large oscule found opposite the attachment point.Stalked reproductive buds are produced between July and September (van Soest et al., 2000).