Blue Sea Star

Linckia, or the blue sea star (Linckia laevigata), is distinguished by its bright blue coloration, which can vary from light blue to dark blue shades. Sometimes individuals with a greenish or purple tint are found. It usually has five rays (arms) that can reach up to 30 cm in length, although individuals with more rays are also found. The body surface is smooth, with small bumps and often covered with small spines.

Linckia inhabits tropical and subtropical waters of the Indo-Pacific region. It is found on coral reefs, among coral debris, and on sandy bottoms at depths from 0 to 60 meters. It is most commonly found in the Great Barrier Reef area, as well as in the waters of Indonesia, the Philippines, Micronesia, and other parts of the Indo-Pacific region.

The blue sea star feeds on microorganisms and organic particles that it finds on the surface of corals and other substrates. The main diet consists of bacterial films and detritus. For feeding, it everts its stomach outward, covers the food object, and then digests it externally.

Linckia reproduces both sexually and asexually. Sexual reproduction occurs through spawning, when males and females release their gametes into the water, where fertilization takes place. The larvae swim in plankton until they settle to the bottom and transform into young sea stars. Asexual reproduction occurs through autotomy: the sea star can detach one of its rays, which then regenerates into a new complete individual.

It is not poisonous and not aggressive. These sea stars are usually slow-moving and do not harm humans. However, divers are advised not to touch sea stars and other marine inhabitants to avoid stress for the animals and potential damage to their delicate skin.