In this article we will discuss about the structure of Peripatus with the help of a diagram.
1. It is a carnivores, predaceous and nocturnal arthropod found commonly in crevices of rocks, under stones and wood in damp tropical regions.
2. Body cylindrical, elongated and without true segmentation and exoskeleton.
3. Skin velvety and is thrown into numerous transverse grooves (wrinkles), which bear spiny papillae.
4. Distinct head is absent but anterior end bears a pair of segmented antennae, a pair of jaws, a pair of eyes and a pair of oral papillae having slime gland at their base.
5. Along the body, on lateral sides, are present about 14 pairs of un-segmented and stumpy appendages for movement.
6. Excretion through nephridia. Sexes are separate and they are mostly viviparous.
7. It is called living fossil and acts as connecting link between Annelida and Arthropoda and exhibits following affinities:
Annelidan affinities:
(a) Presence of paired nephridia.
(b) Presence of straight alimentary canal.
(c) Presence of un-segmented stumpy appendages.
(d) Presence of simple eyes.
Arthropod affinities:
(a) Presence of tracheal system
(b) Presence of chitinous cuticle
(c) Presence of jaws
(d) Presence of antennae