Physical Appearance

Chitons (A species of mollusk.) are amazing creatures and have been around since the Paleozoic era or more specifically the Cambrian period. They have evolved little and are characterized by There 8 calcareous dorsal plants surrounded by a mantle. Their underside is composed of a giant ventral foot that is used for attaching to rocks and movement. (On a side note this makes it near impossible to get them off the rock without hurting them.) As you can see from the picture to the right their understructure is fairly simply and is composed of gills, foot and radula. (The knife like teeth they use to scrape off plants, diatoms, and bacteria off of rocks.)

Habitat

Chiton can be found all around the world. They live in cool, temperate, and tropical waters. Their habitat regardless to climate however is always in the intertidal zone, on rocks, between rocks, and in tide pools. Studies have been shown that most chiton reside in the lower zone thought some species are better adept in the high and mid zones. They are exposed to the same harsh intertidal conditions that all intertidal organisms are exposed to; constant fluctuant in temperature, water level, salinity, ph, and predator populations. Their calcareous plates and giant foot have helped for them to continually be a favorite of natural selection for over 500 million years however and withstand these less than desirable conditions.

Reproduction

Chitons reproduce by releasing eggs (female) and sperm(male) into the ocean. The currents carry the eggs and they are fertilized in the water. They then develop into larvae and then into chiton.

Food source

All chiton are grazers and most are herbivores, but there are some species that are carnivores/omnivores. The non-herbivore chitons graze on microorganisms such as diatoms (please see the picture to the right.).

Importance of Chitons as Primary Consumers

Mollusks fill a unique niche in the intertidal zone as primary consumers. They are one of the most important factors in controlling algae growth, in the intertidal zone. (Bertness) Common mollusks that live in the intertidal zones are snails and chitons. Chitons are especailly important in ecosystems where they are the dominant grazer,(such as bermuda) and have been found to increase the biomass of its prey through grazing. (Littler)

Chiton Movement

Chitons, contrary to their appearance, are able to more relatively quickly. Please watch this video I took from Spittal Pond in Bermuda of a West Indian Chiton moving along a rock crevice.