Icon Sea Star

Overview

The Icon Sea Star (Iconaster longimanus), often called the "Double Star," is a distinctive starfish native to the tropical west and central Indo-Pacific. It is easily recognized by its unique, geometric appearance, which features a star-within-a-star pattern on its upper surface.

Distribution & habitat

This species is found across a broad range including the Philippines, Indonesia, Malaysia, Singapore, the South China Sea, and parts of Australia and southeastern Arabia. It typically inhabits deep reef areas, often favoring lower reef slopes and adjacent seabed regions characterized by rubble or sandy and rocky substrates.

Appearance

The Icon Sea Star is defined by five thin, tapering, and flattened arms radiating from a central disc. Its most striking feature is a marginal row of large, mosaic-like plates that frame the body. These plates often display a contrasting color scheme, typically featuring a tan margin with symmetrical dark brown bands, while the central disc is generally an orange-brown hue.

Biology & behavior

This starfish is generally solitary and moves slowly across the reef. Unlike many other sea stars, it does not actively hunt prey. Instead, it is an omnivorous scavenger that feeds on epilithic growth, detritus, microorganisms, and small benthic invertebrates found on hard surfaces. A notable aspect of its biology is its reproductive strategy: it produces large, yolky eggs that undergo abbreviated development, bypassing the typical free-swimming larval stage found in many other starfish species.