Triactis producta (Boxer crab anemone)


Triactis producta is a small brown sea anemone. The base is about 1 cm in diameter and the column extends to about 1.5 cm in height. At the top there is a crown with roughly 50, long tentacles. Halfway up the column there is a ring of branching, pale brown pseudo-tentacles. On top of theses tentacles there are a few semi-spherical bulges known as vesicles. These can be grey, pink or green and are packed with stinging cells.


Unassessed by the IUCN Red list. It is spread throughout the Indo-Pacific.


Indo-Pacific; from the Red Sea all they way to French Polynesia, South of Japan to Australia. They are commonly found in crevices, ledges, between rubble and on fire corals or stony corals, in a depth range of 0-15 meters.


The anemone can reproduce by asexual cloning.


Up to about 1,5 cm. in height. It grows in clusters of several individuals, so the diameter may vary.

Prey / Predation

Triactis product can feed in two different ways. With its tentacles retracted and its pseudo-tentacles extended, it can photosynthesize by the zooxanthellae in the brown algae within. Energy from the sun is used to build sugars. But at night the tentacles it can actively hunt for small invertebrates with its tentacles, packed with a powerful toxin. The toxin is strong enough to paralyze the victims, allowing the anemone to eat.

Special features

The boxer crab anemone gets its name from the symbiosis with the boxer crab Lybia leptochelis. Juvenile anemones are used by the crab to cover its claws, for protection and stinging attacks. The anemone benefits by feeding along with the crab.