Common name: Chalk Sponge

General information

The Chalk Sponge, scientifically known as Lamellodysidea herbacea, is a species of sponge found in various reef environments. This sponge is notable for its bright green coloration, which is due to the presence of symbiotic cyanobacteria. These cyanobacteria, which live within the sponge's tissues, provide it with additional nutrients through photosynthesis, making it an interesting species for both scientific study and the reefkeeping hobby.

Care

Lamellodysidea herbacea requires specific care to thrive in a reef aquarium. It prefers moderate to strong water flow and low to moderate lighting conditions. The water quality should be high, with low levels of nitrates and phosphates, to prevent algae overgrowth on the sponge's surface. It is important to note that sponges should never be exposed to air, as this can introduce air bubbles into their internal canal systems, which can be fatal.

Reproduction

Sponges, including Lamellodysidea herbacea, reproduce both sexually and asexually. Sexual reproduction involves the release of sperm into the water column, which then fertilizes eggs within another sponge's body. Asexually, sponges can regenerate from fragments, a process known as budding. In the aquarium, fragments that break off can potentially grow into new individuals if conditions are favorable.

Symbiosis

The symbiotic relationship between Lamellodysidea herbacea and cyanobacteria is a classic example of mutualism. The sponge provides a protective habitat for the cyanobacteria, while the cyanobacteria supply the sponge with oxygen and organic compounds produced through photosynthesis. This relationship enhances the sponge's ability to survive in nutrient-poor waters.

Habitat

Lamellodysidea herbacea is typically found in the Indo-Pacific region, including the Red Sea, the Indian Ocean, and the western Pacific Ocean. It inhabits reef slopes and lagoons, often attaching to hard substrates in areas with good water circulation.