Identification
The Leathery Sea Anemone (*Cryptodendrum adhaesivum*) is a visual marvel, often resembling a colorful, flat pizza or a textured carpet hugging the reef. Reaching up to 30cm in diameter, its most distinctive field mark is its "biform" tentacles. Look closely: the inner disc is covered in tiny, branched tentacles that look like miniature heads of cauliflower or grapes. In stark contrast, the outer rim features short, simple, blunt tentacles. While color morphs vary wildly—ranging from neon pink and electric green to mottled gold—the two-toned texture of the tentacle zones is the definitive way to distinguish it from similar-looking *Stichodactyla* carpet anemones.
Habitat & Range
This species is a staple of the tropical Indo-Pacific, found everywhere from the Red Sea and East Africa to the shores of Australia and Polynesia. It is a sun-lover, typically appearing in shallow water (less than 10 meters deep) on reef flats and in lagoons. It prefers to anchor its foot deep into rock crevices or under coral rubble, leaving only its ornate oral disc exposed to the light.
Behaviour & Diet
While it appears stationary, this anemone is a formidable predator. It employs a dual strategy for survival: it "farms" symbiotic zooxanthellae algae in its tissues to harness solar energy, while simultaneously using its potent nematocysts (stinging cells) to snag passing zooplankton and small crustaceans. Unlike other anemones that host a wide variety of fish, this species is famously picky, primarily hosting only the Clark’s Anemonefish (*Amphiprion clarkii*).
Fascinating Fact
Its specific epithet, *adhaesivum*, is a literal warning. This is arguably the stickiest anemone in the ocean. Its sting is so adhesive that if a person touches it, the tentacles will often break off the anemone’s body and remain stuck to the skin, continuing to fire toxins long after contact!