Odontode
Odontodes, or dermal teeth, are hard structures found on the external surfaces of animals or near internal openings. They comprise a soft pulp surrounded by dentine and covered by a mineralized substance such as enamel, a structure similar to that of teeth.[1] They generally do not have the same function as teeth, and are not replaced the same way teeth are in most fish.[2] In some animals (notably catfish) the presence or size of odontodes can be used in determining the sex.[3]
The name comes from the Greek "odon" meaning tooth.
Images
A New Species of Hisonotus (Siluriformes,Loricariidae) of the Upper Rı´o Uruguay Basin (see page 7) An article showing scanning electron microscope images of odontodes on a catfish. Author:Adriana E. Aquino, Scott A. Schaefer, Amalia M. Miquelarena. Publisher: The American Museum of Natural History.