Common name: Caulerpa nummularia

General information

Caulerpa nummularia, commonly known as Button Caulerpa or Green Grape Algae, is a species of green macroalgae that is popular among reef aquarium hobbyists for its unique appearance and utility in nutrient control. This species is characterized by its small, round, and coin-like segments attached to creeping stolons, resembling a string of green buttons or grapes. It is part of the Caulerpaceae family and is known for its fast growth and ability to absorb excess nutrients like nitrates and phosphates from the water, which can help in controlling algae blooms.

Care

Button Caulerpa is relatively easy to grow and maintain in a reef aquarium. It requires moderate to high lighting and a stable environment to thrive. It can be attached to live rock or allowed to root in a sandy substrate. Regular pruning is necessary to prevent it from overgrowing and potentially releasing toxins if it dies back. It's important to monitor its growth and keep it contained, as it can sometimes outcompete other macroalgae or corals for space and resources.

Symbiosis

While Caulerpa nummularia does not have specific symbiotic relationships like those seen in coral and anemone species, it does provide a habitat and refuge for small invertebrates and fish fry. Its dense structure offers protection from predators and a surface for microorganisms to colonize, which can be a food source for various small reef inhabitants.

Habitat

Caulerpa nummularia is found in tropical and subtropical oceans around the world. It typically grows in shallow waters, often in lagoons or along reef flats where it can form extensive mats. This species is adaptable and can be found at various depths, often thriving in areas with good water flow and light penetration.