Acanthochitona zelandica is a species of chiton in the family Acanthochitonidae, also sometimes known as the hairy, or "tufted," chiton. It probably developed during the mid to late Pleistocene, and is endemic to New Zealand.
Acanthochitona zelandica has an oval shaped body, growing up to 30.1 mm in length and 20 mm in width. The individual median valves of the shell, excluding the head and tail, are small, usually no more than 5 mm wide and 4 mm long. The shell and girdle are generally light brown, with darker brown spots across the shell. The girdle is adorned with small bunches of spines for protection, leading to the pseudonyms "hairy" or "tufted" chiton.
Acanthochitona zelandica is found off the coast of New Zealand around the North, South, Stewart, and Auckland Islands, including the Otago Peninsula and the great Bay of Islands. It is less common off the more exposed, west coast beaches. It occupies the intertidal and shallow sub-tidal areas, in depths of up to 10 meters. A. zelandica lives primarily on, underneath, and in the crevices of coastal rocks. It has been observed living in clumps of the Pacific oyster Magallana gigas, most likely to avoid being smothered by increasing mud levels.
While larger chitons have been known to eat large algal blades, encrusting colonial animals, or even engage in predatory behavior to trap and consume mobile animals, Acanthochitona zelandica is a grazer and uses the radula to scrape algal films and built-up diatom layers off of tidal rocks.
