Cryptasterina pentagona

Cryptasterina pentagona is a starfish with a pentagonal shape, characterized by five short rays that have rounded tips. Its surface is rough due to spiky granulations, and the ossicles are arranged in a longitudinal pattern along the rays. The underside is flat, while the upper side forms a gentle dome. This species can be distinguished from the similar Cryptasterina hystera by its reproductive strategy, as Cryptasterina pentagona releases large yolked eggs that develop into planktonic larvae, unlike its viviparous relative. This starfish inhabits the tropical Indo-Pacific region, including areas like Indonesia, the Philippines, the Solomon Islands, Taiwan, Japan, and the northeastern coast of Queensland, Australia. It is typically found in shallow waters, often residing in the littoral and shallow neritic zones, where it hides under rocks in the upper intertidal zone. Its distribution in Australia ranges from Mission Beach to Airlie Beach, with most occurrences reported at depths less than 40 meters. The species has separate sexes, with females releasing buoyant, golden yolked eggs that are fertilized externally. The larvae initially float to the surface before sinking to the seabed, where they attach to a substrate and undergo metamorphosis into juvenile starfish. These juveniles are amber-colored, indicating they still have yolk reserves for nourishment. Divers may encounter this species in shallow waters, where they are often seen resting on the substrate or concealed beneath rocks. The conservation status of Cryptasterina pentagona has not been evaluated.