Fine Hair Anemone – Sarcophinanthus cf. sertus

Fine Hair Anemone, Sarcophinanthus cf. sertus, is an unusual colonial anemone valued for its dense covering of extremely slender tentacles and distinctive grass-like appearance. This specimen displays a broad colony of closely packed polyps with pale cream to pinkish bases and fine green tentacles that create a soft, flowing texture across the surface.

The designation Sarcophinanthus cf. sertus is intentionally conservative. The abbreviation cf. means “compare with” and indicates that the specimen closely resembles Sarcophinanthus sertus, but that a definitive species-level identification has not been established. Sarcophinanthus sertus is the recognized species within the genus Sarcophinanthus.

Unlike a solitary anemone with one large oral disc, this type forms a dense colonial growth composed of numerous individual polyps. Each polyp extends a crown of very fine tentacles, creating the characteristic “fine hair” appearance. When fully expanded, the colony can resemble a patch of waving aquatic grass, adding movement and texture to the reef aquarium.

The green tentacle tips contrast with the paler underlying tissue, and gentle water movement allows the slender tentacles to sway naturally. The colony's appearance can change substantially depending on flow, lighting, and the degree of polyp extension.

Like many shallow-water photosynthetic cnidarians, Fine Hair Anemones rely substantially on symbiotic photosynthetic dinoflagellates for energy. They may also capture very small suspended plankton and particulate foods from the surrounding water.

Because this is a colonial anemone that may spread over available substrate, placement should allow room for expansion. It is best positioned where it receives moderate lighting and gentle to moderate indirect water movement without being continuously blasted by a strong current.

Care Guide

Scientific Identification: Sarcophinanthus cf. sertus
Common Name: Fine Hair Anemone
Care Level: Moderate
Lighting: Moderate
Water Flow: Low to Moderate, indirect and variable
Placement: Lower to middle areas of the aquarium depending on lighting intensity
Temperament: Semi-aggressive; provide adequate space from neighboring corals and anemones
Reef Compatibility: Generally suitable for reef aquariums with appropriate placement and spacing
Feeding: Primarily photosynthetic; may also capture very small planktonic and suspended particulate foods
Growth Form: Colonial growth consisting of numerous closely packed polyps with very slender tentacles
Water Parameters: Maintain stable marine aquarium temperature and salinity with consistent alkalinity and nutrient levels. Avoid rapid changes in water chemistry.
Special Considerations: Provide enough surrounding space for the colony to expand and potentially spread onto nearby substrate. Gentle to moderate variable flow helps keep debris from settling while allowing the fine tentacles to extend naturally. Avoid strong direct flow that continuously bends or retracts the polyps. Acclimate gradually when introducing the colony to stronger lighting.