THE CORAL ID DIRECTORY | Rock Flower Anemones

Phymanthus Crucifer

Alkalinity: 8.0-11.5 dKH
Calcium: 400-450 ppm
Magnesium: 1350 ppm
Phosphate: 0.00-0.08 ppm
Nitrate: Low
Flow: Low to Moderate
Lighting: Low to High
Placement: Substrate to Low Rockwork

These Rock Flower ‘nems were kept under actinic LED’s only.


Scientific Name: Phymanthus Crucifer
Common Aliases: Rock Flower Anemone – Rock Flower ‘Nem
Growth Pattern: N/A
Care Level: Beginner – requires control of P04 & N03
Lighting: Substrate – Low Rock work with LED or Halides
Flow: Moderate to low indirect flow
Most Sensitive to: Acclimation and placement 
Common Problems: Easily covered by blowing substrate.
Where to Start: Low nitrates and phosphate, place in rock rubble patch.


Rock Flower Anemones have an almost frilly appearance and come in a variety of colour combinations.

Like other anemones it will bury it’s foot deep within rock crevices or  substrate with only it’s oral disc on the surface. Typically reaching only 3-4″ in diameter these small anemones are well suited for nano reef tanks. Regular feedings of meaty foods will increase growth rates. This small photosynthetic anemone requires moderate lighting conditions and low, indirect flow. Ideal placement is in rocky substrate or the bottom section of the tank with indirect lighting. Nitrate and phosphate levels should be kept low prior to adding anemones to the tank.

Lighting & Water Flow:

Actinic or blue spectrum lighting, especially LED’s, will bring out unusually bright fluorescent colours in these other wise drab looking anemones. They can tolerate a wide range of lighting, but we’ve found medium and direct actinic lighting to be best. These specific anemones were kept under LED lighting approximately 18-24″ under the light fixture.

  • Low Light = 30-50 PAR
  • Medium = 50-150 PAR
  • High Light = 150+ PAR

Low, indirect water movement is recommended to keep the anemone’s oral disc free from debris and to allow small meaty particles to pass by for it to feed on. Never aim a powerhead directly at an anemone as this can cause harm. Heavier substrates are recommended as blowing sand can bury the anemone.

Feeding & Growth:

Rock Flower Anemones are photosynthetic invertebrates that rely on food from the symbiotic zooxanthellae algae they host within their tissue. However, they will readily accept small supplementary meaty foods i.e frozen mysis or clam. Interestingly, this anemone reproduces sexually and documented spawnings have been recorded in the aquarium. The female of the species will release the young at varying stages of

development, but usually when at least 6 tentacles are visible. The baby anemones tend to stay near/under the female anemone as they grow.

Regularly feedings can increase growth rates significantly. Care should be taken in systems with already high nutrient levels. Regularly feeding your tank can also increase the need for water changes due to the regular addition of nitrate and phosphate sources.

Other Notes:

It has been noted that treating a system for flatworms caused the death of many rock flower anemones. Possibly due to the toxins released by the dying flatworms. Caution is advised when dosing any medications or treatments to a system that contains invertebrates.