TankBud

Tube anemone

Cerianthus sp.

Also known as Cerianthid, Colored Tube Anemone, Fire Tube Anemone

SaltwaterAnemone

Tube anemone (Cerianthus sp.)
Parent Géry · CC BY-SA 3.0

Care at a glance

Temperature
75–81°F
24–27°C
pH
8.1–8.4
Adult size
7.9 in
20 cm
Minimum tank
20 gal
75 L
Temperament
Aggressive
Social behavior
Solitary
Tankmates
With caution
Swim level
Bottom
Diet
Carnivore
Difficulty
Medium
Breeding
No record
Rarity
Common
Reef safe
Not reef safe
Family
Cerianthidae
Origin
Soft sand and mud seafloors worldwide (tropical to temperate seas)

Overview

The tube anemone is a burrowing predator that lives in a tube in deep sand, best kept away from small fish. It is a step up from the easiest invertebrates.

Did you know

A tube anemone can vanish into its tube almost instantly when startled, faster than any true anemone can close up. That reflex makes it good at ambushing a fish that gets too curious about its feathery tentacles.

Caring for the tube anemone

Lighting is not a requirement for a tube anemone, since it is not photosynthetic. Many keepers run actinic blue light in the evening, because the tentacles fluoresce strongly under it. It needs a very deep sand bed, ideally 10 cm or more, or a dedicated deep sand patch built into the rockwork. Place it where digging fish and foraging crabs will not disturb it.

Light to moderate flow that carries food past the crown is enough. Keep the water at 75 to 81°F (24 to 27°C) with a pH of 8.1 to 8.4. It needs a tank of at least 20 gal (75 L). Feed it small meaty foods such as mysis or brine shrimp several times a week, since it has no other energy source.

The tube anemone is not reef safe. Its outer tentacle crown extends much wider than it looks and carries a real sting. Hobbyists regularly report it catching and eating small, slow-moving fish, especially gobies, blennies and firefish that settle too close, along with ornamental shrimp. It does not host clownfish and is more of a predation risk than a benefit to a small or juvenile clownfish.

Give it its own patch of sand well away from other fish and invertebrates, with no coral anywhere near its full reach. Acclimate it gently, since it does not tolerate being handled out of water.

Good to know

Despite the common name, the tube anemone is not a true sea anemone. Cerianthus belongs to its own order, Ceriantharia, a separate lineage of hexacorals that never evolved a pedal disc. Instead it builds a permanent tube to live in. It carries two rings of tentacles. A long outer crown stings and captures food, and a short inner ring around the mouth moves that food inward. Unlike a true anemone it cannot fully retract its oral disc, only withdraw into its tube. It is azooxanthellate, meaning it has no symbiotic algae.

In the wild

Cerianthus species live worldwide on soft sand and mud seafloors, in tropical to temperate seas. They burrow deep and build a felt-like tube from secreted mucus and specialized stinging threads.

Common questions

What size tank does a tube anemone need?

A tube anemone needs at least 20 gal (75 L).

What temperature and pH does a tube anemone need?

A tube anemone is comfortable at 75–81°F (24–27°C) with a pH of 8.1–8.4.

What does a tube anemone eat?

A tube anemone eats small meaty foods such as mysis or brine shrimp, offered several times a week. It also catches small fish and ornamental shrimp that settle too close.

How big does a tube anemone get?

An adult tube anemone reaches about 7.9 in (20 cm).

Related species