- a ring or saddle-shaped region of glandular tissue in the body wall of certain annelids, as earthworms and some leeches, that after copulation secretes a cocoon in which the eggs and sperm are deposited for fertilization and development.
Origin of clitellum
Examples from the Web for clitellum
Historical Examples of clitellum
Clitellum not present as a definite organ, as in Oligochaeta.
Clitellum, kli-tel′um, n. the saddle of an annelid, as the earthworm:—pl.
Clitellum always present, extending over two (many limicolous forms) to forty-five segments (Alma).
Clitellum generally only two or three segments and more anterior in position than in Terricolae.
Clitellum commonly extensive and more posterior in position than in other groups.
- a thickened saddle-like region of epidermis in earthworms and leeches whose secretions bind copulating worms together and later form a cocoon around the eggs
Word Origin for clitellum
"raised band around an earthworm," 1816, Modern Latin, from Latin clitellae "a pack-saddle," diminutive of *clitra "litter," from PIE *klei-tro-, from root *klei- (see lean (v.)). Related: Clitellar.