Giant Chiton

Plaxiphora albida

Plaxiphora albida, known as the Giant chiton, is a distinctive species characterized by its dark green to brown, humped, oval-shaped shell composed of eight rough valves. It typically reaches a length of about 95 mm, with a range between 40 to 100 mm and a width of 25 to 38 mm. The chiton's girdle is leathery and brown, adorned with darker bars and long bristles, distinguishing it from other chiton species. This species is predominantly found along the rocky shores of south-western Australia, including regions like Queensland, New South Wales, Victoria, and Tasmania, usually inhabiting low-shore algal communities at depths shallower than 40 meters. Feeding primarily on algae, Plaxiphora albida also consumes sponges, corals, and tunicates. It possesses radular, bulbous teeth that are iron-biomineralized, enhancing their ability to scrape food from hard substrates. The reproductive cycle of this chiton involves fluctuations in gonad size throughout the year, with peak maturity observed in January. Recruits are typically found in late autumn, and the species reaches reproductive maturity around two years of age. While Plaxiphora albida is relatively abundant, it faces threats from ecological shifts such as temperature changes and tidal action, which can affect its shell integrity. Despite these challenges, the species has demonstrated resilience over millions of years, contributing to its ongoing presence in the marine ecosystem.