Common name: Triactis
Triactis is a genus of sea anemones belonging to the family Aliciidae, and it is monotypic, containing only one species, Triactis producta. This fascinating anemone is native to the shallow waters of the tropical Indo-Pacific, ranging from the Red Sea and Mozambique to Hawaii and French Polynesia. It is often found in crevices or concealed among stony corals, forming dense clusters that are likely clones of a single individual.
One of the most intriguing aspects of Triactis is their mutualistic relationship with boxer crabs of the genus Lybia. These crabs hold small Triactis anemones in their claws, using them as both a defensive weapon and a tool to capture prey. If a crab loses one of its anemones, it can split the remaining one in half, and each part will regenerate into a new individual. This symbiotic relationship benefits both the crab and the anemone, as the crab gains protection and assistance in feeding, while the anemone is provided with mobility and access to food.
In the aquarium hobby, Triactis are rarely kept due to their small size and cryptic nature. Additionally, they are one of the most venomous sea anemones in the Red Sea, with stings causing prolonged pain, swelling, and skin sensitivity. Their venom is highly stable and resistant to heat and chemicals, making it a genus best admired in their natural habitat rather than in captivity.
