I decided to check out these west coast tidal pools today and saw some odd organisms.
The Chiton is a mysterious creature with eight protective shell plates and a muscular foot, which anchors it to a rock. It is impossible to pry it off the rock with your bare hands.
Chitons are generally sluggish and many are nocturnal and remain concealed under rocks during the day. Their food mainly consists of algae scraped off the rocks, but some also consume animal matter. Its shell plates are often broken, but it can repair such breaks. When exposed to air during low tide, a Chiton can breathe oxygen from the atmosphere.
Recently it has been discovered that this armored relative of snails is unique among living animals, because it sees the world through lenses of limestone, and its eyes literally erode as it gets older. Chitons may be the only living animals with rocky eyes of this sort. Another group of extinct oceanic animals – the trilobites – had lenses made from calcite, another form of limestone.
