A chaeta or cheta (from Ancient Greek χαίτη (khaítē) 'crest, mane, flowing hair'; pl. chaetae) is a chitinous bristle or seta found on annelid worms, although the term is also frequently used to describe similar structures in other invertebrates such as arthropods.

If an earthworm is drawn over the tips of the fingers, a roughness will be felt although the surface appears smooth and glistening. This roughness is due to the presence of bristles called chaetae or setae.

New chaetae are formed throughout the life of the worms, and distribution of different kinds of chaetae along the body is carefully controlled and changes as the worm grows. In rows of identical chaetae, new chaetae are produced at one end of the fascicle and migrate through the fascicle and drop out at the other end (e.g., hooks in terebellids).

to front will reveal a rough surface as you brush against the backward-pointing chaetae. These chaetae enable the worm to grip and because of these chaetae, most earthworms belong to a group called the oligochaetes.

Feb 23, 2020 · Common earthworms clearly showing body segments, with visible chaetae. Normally, as in the common earthworms, Oligochaetes have 8 small chaetae per body segment. These are usually arranged in four groups of two around the body.

Nov 23, 2024 · Chitinous hairlike extensions, anchored in the epidermis and projecting from the cuticle, called setae/chaetae are present in every segment. Annelids show the presence of a true coelom, derived from embryonic mesoderm and protostomy. Hence, …

Annelids show the presence of a true coelom, derived from embryonic mesoderm and protostomy. Hence, they are the most advanced worms. A well-developed and complete digestive system is present in earthworms (oligochaetes) with a mouth, muscular pharynx, esophagus, crop, and gizzard being present.

Chaetae (also called setae) are earthworms' locomotion structures and protrude from spots placed laterally and ventrally on every segment of the worm, except the first and the last ones (Sims & Gerard 1985, Edwards & Bohlen 1996, Morgan 2001).

Chaetae, hairs, bristles. As their scientific name suggests Oligochaetes have fewer chaetae Bristly hairs) than Polychaetes; usually they have four pairs of chaetae on each segment. The chaetae are used in burrowing as they provide anchor points (see the drawings above and below).

Chaetae are bristle-like structures that are primarily found in annelids, such as earthworms. They are used for locomotion, providing traction and grip on surfaces. On the other hand, setae are hair-like structures found in arthropods, including insects and spiders.