Fig Sponge

Overview

The fig sponge (Suberites ficus) is a highly variable marine sponge known for its diverse growth forms, which can range from massive, lobed, or globular structures to cushion-like or encrusting shapes. Typically found in the northeast Atlantic and Mediterranean, it is a filter-feeding organism that plays a key role in benthic communities by providing habitat structure.

Appearance

This sponge is generally vibrant orange, though its color can shift to yellow, brown, white, or even greenish hues depending on environmental conditions and the presence of symbiotic algae. It features a smooth, slightly rough surface and large, prominent oscules (water-exit pores) usually located at the tops of its lobes. When removed from the water, the sponge noticeably contracts to about three-quarters of its original size.

Distribution & habitat

Suberites ficus is widely distributed throughout the northeast Atlantic, including the North Sea and British Isles, as well as the northwestern Mediterranean. It thrives on hard surfaces such as rocks, wreckage, and empty shells, often preferring areas exposed to tidal currents.

Biology & behavior

As a filter feeder, it draws water through its body to extract nutrients and oxygen. The species reproduces oviparously, releasing eggs in October, and develops indirectly via parenchymella larvae. It is sometimes observed in association with other marine life, such as cephalopod egg masses, and can grow over and eventually dissolve the shells of dead mollusks.