[Polychaeta] Chitinous bristle protruding from a pocket in the body wall (types of setae).

[Crustacea general] A bristle, spine- or hair-like structure, with basal socket, and produced as an extension of the cuticle; mostly on appendages; setal shaft may be smooth (simple seta), or feathery (plumose seta). Setae are longer and thicker-walled than hairs, longer and more flexible than teeth or claws. Their structure, number and morphology are usually consistent within a species.

[Ostracoda] Individual setae are often referred to by a consistent notation of letters (e.g., "a" or "e" seta etc.). Illustrations of nomenclature of the setae in halocyprid ostracod:

adult female, fr. organ/1st ant
male frontal organ /1st ant ov
female, 2nd antenna
male endopodite of 2nd antenna

See also f-j seta
See also setule

Alternative forms for Seta : Setae (pl.), [Ostracoda] Setaenatatory seta, [p][/p].