"Diagrams of various earthworms to illustrate external characters. A, B, C, anterior segments from the ventral surface; D, hinder end of the body of Urochaeta." (Britannica, 1910)

Earthworm

"Diagrams of various earthworms to illustrate external characters. A, B, C, anterior segments from the…

The earthworms are also known as megadriles, in the families Tubificidae, Lumbriculidae, and Enchytraeidae, among others. The basic body plan is a tube, the digestive system, within a tube, the muscular slimy, moist outer body. The body is annular, formed of segments that are most specialized in the anterior and have a simple circulatory system. They have two main blood vessels that extend through the length of their body: a ventral blood vessel which leads the blood to the posterior end, and a dorsal blood vessel which leads to the anterior end. The dorsal vessel is contractile and pumps blood forward, where it is pumped into the ventral vessel by a series of "hearts" (aortic arches) which vary in number in the different taxa.

Earthworm

The earthworms are also known as megadriles, in the families Tubificidae, Lumbriculidae, and Enchytraeidae,…

The earthworms are also known as megadriles, in the families Tubificidae, Lumbriculidae, and Enchytraeidae. Earthworms have a pair of kidneys to every segment, each consisting of a coiled tube wrapped in a mass of small blood vessels, and at its inner end communicating with the body cavity by means of a funnel-shaped opening. Here is a diagram of an earthworm kidney., showing (b) blood vessel, (f) funnel opening into body cavity, (o) outer opening, (s)septum, (w) body wall

Earthworm Anatomy

The earthworms are also known as megadriles, in the families Tubificidae, Lumbriculidae, and Enchytraeidae.…

An illustration of the various types of earthworm setae. Seta (plural: setae) is a biological term derived from the Latin word for "bristle". It refers to a number of different bristle- or hair-like structures on living organisms. "A, penial seta of Perichaeta ceylonica; b, extremity of penial seta of Acanthodrilus; c, Seta of Urochaeta; d, Seta of Lumbricus; e, Seta of Criodrilus; f, g, Setae of Bohemilla comata; h, i, j, Setae of Psammoryctes barbatus." (Britannica, 1910)

Setae of Earthworm

An illustration of the various types of earthworm setae. Seta (plural: setae) is a biological term derived…