Golf Ball Sponge

Overview

The Golf Ball Sponge (Tethya aurantium) is a distinctive, spherical marine sponge that closely resembles a small orange. It is typically found attached to rocky substrates in shallow coastal waters, often appearing in shades of yellow or bright orange.

Appearance

This sponge is characterized by its firm, elastic, and warty surface, which is covered in small tubercles separated by contractile grooves. It typically features a single, prominent osculum (exhalant opening) located at the top, opposite its point of attachment. The body is supported by internal spicules, which can cause skin irritation if handled. When contracted, the surface may appear smoother with visible striations.

Distribution & habitat

Tethya aurantium is widely distributed, occurring in the Mediterranean Sea, the North Eastern Atlantic, and parts of the African coast. It thrives in various rocky environments, including kelp forests and shaded cave walls, ranging from the low intertidal zone down to depths of 130 meters.

Biology & behavior

As a filter feeder, this sponge draws water through surface pores to capture microscopic plankton. It is known for its ability to contract its body, which helps regulate water flow and surface appearance. During the reproductive season, the sponge may produce small, stalked buds on its tubercles, which serve as a form of asexual reproduction.