Haddon's Anemone

Overview

Haddon's Anemone (Stichodactyla haddoni) is a large, carpet-like sea anemone widely distributed across the tropical and subtropical waters of the Indo-Pacific, including the Red Sea. It is well-known for its symbiotic relationships with various species of clownfish and certain crustaceans, which find protection among its tentacles.

Appearance

This species features a highly folded, wavy oral disc that typically measures 50–80 cm in diameter. The surface is covered in short, sticky, bulb-shaped tentacles that are usually yellowish or tan, though they can appear in shades of green, gray, or rarely, blue and pink. A small, tentacle-free area surrounds the mouth. The thick column, which may be visible when the anemone is retracted, is covered in small, non-adhesive bumps known as verrucae.

Distribution & habitat

Haddon's Anemone is found throughout the Indo-Pacific region, ranging from the Red Sea and Mauritius to Fiji, and from southern Japan down to Australia. It prefers sandy or silty substrates, where it often anchors itself in soft bottoms.

Biology & behavior

This anemone utilizes two primary methods for nutrition: it hosts symbiotic zooxanthellae within its tissues to gain energy through photosynthesis and actively captures small prey, such as invertebrates and juvenile fish, using toxins in its sticky tentacles. It is a popular host for several clownfish species, providing them with a safe haven, while also supporting various symbiotic shrimp species.