Identification
The *Actinoporus elongatus*, often called the Rayed Anemone, is a master of seafloor camouflage. Unlike the long, flowing tentacles of its famous cousins, this anemone features an oral disc—up to 30cm in diameter—covered in short, blunt, wart-like vesicles. These vesicles are arranged in precise radial rows, creating a "pavement" or mosaic-like texture that mimics a flat stone or a patch of algae. Its coloration is a mottled palette of olive greens, sandy beiges, and chocolate browns. To tell it apart from the common Carpet Anemone (*Stichodactyla*), look for those distinct "spoke-like" radial lines radiating from the central mouth; *Stichodactyla* is far more uniform and "fuzzy" in appearance.
Habitat & Range
This species is a specialist of the tropical Indo-Pacific, ranging from the shores of East Africa to the waters of Northern Australia and the Philippines. You won’t find it clinging to coral heads; instead, it prefers the soft life. It inhabits shallow, calm environments like sandy lagoons, muddy tidal flats, and lush seagrass meadows.
Behaviour
The Rayed Anemone is a burrower. It anchors its long, muscular column deep into the sediment, often attaching to a buried piece of rubble or shell. In the field, the most striking behavior you’ll witness is its "disappearing act." When disturbed or exposed by a receding tide, it can retract its entire body beneath the sand with startling speed, leaving nothing but a faint circular depression.
Diet
An opportunistic ambush predator, it uses its "sticky" vesicles to snag passing prey. The vesicles are packed with potent nematocysts (stinging cells) that paralyze small fish and crustaceans on contact. Once the prey is secured, the edges of the disc curl inward, funneling the meal toward the central mouth.
Fascinating Fact
The sting of *Actinoporus elongatus* is legendary among beachcombers; it is one of the few anemones whose sting is powerfully felt by humans, often described as a sharp, electric-like burn that can cause skin irritation for days!