About Cryptoconchus porosus (Burrow, 1815)
Cryptoconchus porosus is a large chiton that reaches a length of about 45–75 millimetres (1.8–3.0 in). Adults of this species have eight valves that are almost completely covered by a raised girdle, while young specimens may only have seven. The valves themselves are pale blue or white on top, and sometimes sky blue underneath. When each valve is removed from the animal, it resembles a butterfly, which gives the species its common name. The girdle is fleshy and smooth, with short sutural bristles that protrude from 18 rounded pores. These pores are elevated and run in two crested rows from the head to the tail of the chiton. The colour of the dorsal surface of Cryptoconchus porosus can range from dark brown to bright orange; the underside of the girdle is pale orange, and the foot is bright orange. Cryptoconchus porosus is native to New Zealand and is also found in Madagascar. These common grazers prefer outer exposed rocks washed by waves, located in the low intertidal zone, the shallow subtidal zone, or in deeper water down to 30 metres. They are often found living in association with sponges.
