Symbiosis

Being a sponge, Cliona houses several organisms including fish, ophiuroids (brittle stars) and shrimp. This provides shelter and protection from potential predators and environmental disturbances by acting as a refuge and habitat recruitment platform (Miller et al. 2010).

Cliona has a symbiotic relationship with zooxanthellae, a photosynthetic dinoflagellate (Symbiodinium spp.). The presence of symbiotic zooxanthellae may influence Cliona’s shallow water habitat as these symbionts are photosynthetic, thus needing readily available light. In terms of sponges, the symbiotic relationship between zooxanthellae is restricted to the Clionidae family (Schonberg 2003).

An indirect relationship with parrot fish also  appears to occur, helping Cliona to encrust corals. Parrot fish are seen more as a benefit to Cliona than a threat, as it increases the spread of Cliona when biting at the coral-sponge interface by removing live coral in front of it (Marquez and Zea 2012). 

However, this effect varies depending on the coral species Cliona inhabits as in the Caribbean, C.tenuis was found to grow quicker on one type of coral but not the other (Lopez-Victoria and Zea 2005). However, this hypothesis is hard to determine based on a superficial study, as several other contributing factors may be present as a deeper ecological relationship exists between the sponge, fish and coral, than what is observed.