Green Tube Anemone (Cerianthus membranaceus)

The Green Tube Anemone is a beautiful and unique addition to marine aquariums, admired for its long, flowing green tentacles that sometimes display hints of blue or purple under aquarium lighting. Unlike traditional anemones, the Green Tube Anemone resides in a soft, self-made tube that it buries in the sandy substrate, extending its vibrant tentacles to capture food. With proper care and placement, this anemone is a captivating yet low-maintenance species, ideal for adding movement and color to a well-established aquarium.

Care Information

• Maximum Size: Tentacles can extend up to 12 inches or more.
• Tank Size: 30 gallons minimum; requires a deep sandy substrate for burrowing and an open area for its tentacles to extend freely.
• Diet: Carnivorous; primarily feeds on meaty foods like mysis shrimp, brine shrimp, and finely chopped seafood. Target feeding a few times per week will help maintain health and coloration.
• Water Temp: 72-78°F.
• Salinity: 1.020-1.025.
• Aggression: Semi-aggressive; its tentacles can sting nearby corals or other tank inhabitants if placed too close. Providing ample space is essential to prevent accidental stings to neighboring species.
• Skill Level: Intermediate; requires stable water parameters, deep substrate for anchoring, and regular feedings to thrive.
• Reef Compatibility: With caution; while it doesn’t directly harm corals, its long tentacles can sting invertebrates or corals if they come into contact, so placement is key.

Special Requirements - Deep Sand Bed and Open Space
The Green Tube Anemone requires a deep sandy substrate to anchor its tube securely. Its tentacles need ample space to extend, so it’s best placed in a low-traffic area of the tank to prevent accidental contact with other inhabitants.

Compatibility
This anemone is best suited for fish-only or carefully planned reef tanks where its tentacles have space to extend without impacting other species. It can coexist with peaceful fish that won’t disturb its tentacles, but should be kept away from other corals or invertebrates that could be stung.

Coloration

• Indo-Pacific Region: The Green Tube Anemone often displays vibrant green tentacles, occasionally with subtle blue or purple undertones, adding a striking visual element to the aquarium​.

Typical Habitat

• Distribution: Native to the Indo-Pacific, particularly in sandy reef zones, where it burrows into the substrate and extends its tentacles to capture food. In aquariums, it thrives in tanks with deep sand beds and stable water conditions.