
A girdle is part of the
anatomy
Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...
of a
chiton
Chitons () are marine molluscs of varying size in the class Polyplacophora ( ), formerly known as Amphineura. About 940 extant and 430 fossil species are recognized.
They are also sometimes known as sea cradles or coat-of-mail shells or suck ...
, one class of marine
mollusk
Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...
s, the class
Polyplacophora.
Characteristics
The shell of a chiton consists of eight
valves which articulate with one another. The girdle is a strong but flexible structure that in most cases encircles the plates, holding them all together.
Details of the external surface of the girdle are often useful in identifying the
taxonomic family, genus and species of chiton. For example, the girdle may be covered in overlapping scales, spikes, or it may have tufts of glassy bristles protruding from it.
In a few genera of chitons, the girdle covers the valves either partially, as in the
Black Katy chiton, or completely, as with the
gumboot chiton.
References
{{reflist
Glossary entry for molluscan terminologySome general info on chitons
Mollusc anatomy