The terminal joint or movable piece at the end of the abdomen of Crustacea and other articulates. See Thoracostraca.

the posterior end of the body of higher crustaceans.

seventh segment of the crayfish's abdomen: useful in backward swimming

The terminal segment of a crustacean's body, bearing the anus. In isopods, the telson is fused to the anterior pleonite(s).

a terminal flap of two nearly separated lobes, but often fused into a single plate, and always present in Amphipoda

the plate attached to the sixth abdominal segment (urosome 3) and covering the anus. The morphology of the telson (i.e. shape, ornamentation, degree of cleft ness) is important to taxonomic keys. See figure

Tail portion of a crustacean

terminal (posterior) portion of abdomen. caudomedian element of "tail fan".

middle lobe of the tail fin

(tel - sun) In horseshoe crabs, the telson is the tail.

The last segment of the abdomen in many arthropods. May be flat and paddlelike, buttonlike, or long and spiny, as in the horseshoe crabs.

The telson is the last division of the body of a crustacean. It is not considered a true segment because it does not arise in the embryo from teloblast areas as do real segments. It never carries any appendages, but a forked "tail" called the caudal furca is often present.