Acanthopleura spinosa

Acanthopleura spinosa is a species of chiton that can be identified by its distinctive shell, which can reach a maximum length of 9.0 cm. The shell is composed of eight overlapping plates, providing a unique texture and appearance that differentiates it from other chitons. This species typically seeks shelter within crevices during low tide, making it somewhat cryptic in its behavior. It is commonly associated with Saccostrea cucculata, a type of oyster, which may provide additional habitat structure in its environment. This chiton is found in the Indo-West Pacific region, thriving in tropical waters ranging from 22°S to 27°N and 117°E to 169°E. It is primarily a benthic species, residing in rocky habitats and areas where it can find refuge from predators. While specific depth ranges are not provided, it is generally found in coastal environments where it can graze on algae and other organic matter. In terms of reproduction, Acanthopleura spinosa is gonochoric, meaning individuals are either male or female. The life cycle includes the hatching of eggs into planktonic larvae, which eventually settle on the ocean floor as young adults. Encounters with this species during dives may involve observing it clinging to rocks or hiding among crevices, often requiring careful searching to spot due to its cryptic nature. The conservation status of Acanthopleura spinosa has not been evaluated by the IUCN, and it is considered harmless to humans. Its presence in various dive sites suggests that it is not currently threatened, although ongoing monitoring of its habitat is essential for future assessments.