Characteristics: Chitons are characterised by their eight calcareous plates that are embedded in their dorsal surface. The Gumboot Chiton is usually dark reddish-brown in colour. The tough girdle that completely overgrows the plates is bristly and leathery in texture. The chiton has a large muscular foot and feeds using the radula.
Diet: Chitons, like limpets, are grazers that feed using their rasping radula. The radula consists of two rows of sharp teeth that function by scraping algae and benthic diatoms off rock surfaces.
Reproduction: Chitons are dioecious, which means there are both male and female chitons. The male releases the sperm into the water as shown in the video above, and it is taken up by the females. Fertilised eggs are shed singly or in gelatinous strings. The eggs develop into trochophore larvae before they metamorphose into the adult chiton form.
Common Name: Gumboot Chiton
This video shows the gumboot chiton in several locations at Race Rocks. Note the gills under the mantle on each side of the large foot. Of particular interest is the rare sequence taken at one meter depth in the surging water right off the docks, showing a male shedding gametes into the water.
Locomotion: Chitons have a broad and flat muscular foot which functions in adhesion as well as locomotion. Chitons move slowly and gradually by waves of muscular activity called ‘pedal waves’. The plates fuction to help them attach onto curved surfaces of the rocky intertidal zone.
Longevity: Gumboot chitons can live for approximately 20 years and can grow up to 30cm.
Other Members of the Phylum Mollusca at Race Rocks.
|Return to the Race Rocks Taxonomy
and Image File
|The Race Rocks taxonomy is a collaborative venture originally started with the Biology and Environmental Systems students of Lester Pearson College UWC. It now also has contributions added by Faculty, Staff, Volunteers and Observers on the remote control webcams.|
original by: Sarah Mason PC yr 28