Yellow Cave Sponge

Aplysina cavernicola

The Yellow Cave Sponge, Aplysina cavernicola, is a sponge species found primarily in the Mediterranean Sea. It thrives in cave environments and under overhangs, forming clumps up to 30 cm across. The sponge's structure consists of a base that adheres to hard surfaces, with finger-like projections extending up to 6 cm long. These projections have a sparse covering of small conical protrusions due to embedded horny fibers. Unlike many sponges, it lacks spicules, relying on a mesh of spongin fibers for structural support. The sponge is characterized by its yellowish color. Aplysina cavernicola is a hermaphroditic organism, releasing ciliated parenchymella larvae into the water. These larvae settle on a suitable substrate and transform into juvenile sponges. The species accumulates brominated isoxazoline alkaloids, making it distasteful to certain fish like the sphinx blenny, while other sponges are more readily consumed. These compounds may also provide antimicrobial benefits, protecting the sponge from bacterial pathogens. Divers encountering the Yellow Cave Sponge may find it in locations with depths shallower than 100 meters, as 90% of recorded occurrences are within this range. The sponge is sessile and harmless to humans, making it an interesting subject for underwater observation. Its conservation status has not been evaluated by the IUCN.