Common name: Night anemone

General information

Phyllodiscus semoni, commonly known as the Night Anemone or Semon's Anemone, is a unique and fascinating species of sea anemone. Unlike many other anemones, it is nocturnal, extending its tentacles at night to feed. During the day, it retracts its tentacles and resembles a nondescript lump on the reef, which helps it avoid predators. Its coloration can vary widely, including shades of brown, red, or green, often with fluorescent tips that can be quite striking under actinic aquarium lighting.

Care

Caring for Phyllodiscus semoni can be challenging due to its nocturnal nature and specific feeding requirements. It is best suited for experienced aquarists who can provide a stable environment with low to moderate lighting and water flow. Feeding should occur at night when the anemone is active, offering a diet of small fish, plankton, and other meaty foods. It's important to monitor water quality closely, as this species is sensitive to changes in water parameters.

Reproduction

Reproduction in Phyllodiscus semoni is not well documented in home aquariums. In the wild, they reproduce both sexually, by releasing gametes into the water column, and asexually, through pedal laceration, where new anemones form from pieces of the parent's base.

Symbiosis

Phyllodiscus semoni does not typically engage in the well-known symbiotic relationships with clownfish or other fish species. However, it may host a variety of commensal organisms, such as certain shrimp and crabs, which find refuge among its tentacles and may help keep the anemone clean from debris and parasites.

Habitat

This species is found in the Indo-Pacific region, from the Red Sea to Japan and Australia. It prefers reef slopes and lagoons, often attaching to hard substrates or hiding in crevices. In the aquarium, it requires a similar environment with plenty of hiding places and a substrate suitable for anchoring.