The annelids (/ ˈænəlɪdz /), also known as the segmented worms, comprise a large phylum called Annelida (/ əˈnɛlɪdə /; from Latin anellus 'little ring'). [3][a] The phylum contains over 22,000 extant species, including ragworms, earthworms, and leeches.

2024年12月26日 · Annelid, any member of a phylum of invertebrate animals that are characterized by the possession of a body cavity (or coelom), movable bristles (or setae), and a body divided into segments by transverse rings, or annulations, from which they take their name.

Annelids range in length from less than 1 millimeter to over 3 meters. They never attain the large size of some mollusks. Like mollusks, however, they have a coelom. In fact, the annelid coelom is even larger, allowing greater development of internal organs. Annelids have other similarities with mollusks, including:

2024年10月2日 · Phylum Annelida is a diverse group of organisms within the animal kingdom. They are commonly known as segmented worms or annelids, and they exhibit a wide range of adaptations and lifestyles.

2024年12月27日 · Phylum Annelida (L., annelus = little ring or F., anneler = to arrange in rings) is a group of bilaterally symmetrical, coelomate, and segmented animals known commonly as segmented worms. Members of this phylum exhibit a body divided into repeated segments called metameres, which give them structural and functional division.

Annelids are classified as segmented worms that belong to the invertebrate phylum of animals. There are over 20,000 species of annelids with a variety of individual characteristics that have been discovered so far, but zoologists suspect hundreds of annelids exist in remote jungles and ocean depths that have yet to be identified.

Types of annelids. When many people think of annelids, they limit themselves to earthworms. But there are many examples of annelid species and we provide some of them with information and photos.

2024年12月26日 · Annelid - Segmentation, Setae, Metamerism: The body of an annelid is often described as a tube within a tube. The body form of polychaetes varies, depending on whether the polychaete is free-moving, sedentary, or pelagic (ocean-dwelling).

2024年8月1日 · Annelids, commonly known as segmented worms, are soft-bodied, bilaterally symmetrical invertebrates of the phylum Annelida. They constitute the earthworms, leeches, and ragworms, traditionally grouped into polychaetes, oligochaetes (including earthworms), and …

annelid , Any member of a phylum (Annelida) of invertebrate animals that possess a body cavity (coelom), movable bristles (setae), and a body divided into segments by crosswise rings. Known as segmented worms, annelids are divided into three classes: marine worms (Polychaeta; see polychaete), earthworms (Oligochaeta), and leeches (Hirudinea).