Aselloidea Stenetrioidea Janiroidea Gnathostenetroidoidea Asellota is a suborder of isopod crustaceans found in marine and freshwater environments.

[2] Roughly one-quarter of all marine isopods belong to this suborder.

[3] Members of this suborder are readily distinguished from other isopods by their complex copulatory apparatus.

Other characteristics include six-jointed antennal peduncle, the styliform uropods (a character shared with some other isopod groups), the fusion of pleonites 5, 4 and sometimes 3 to the pleotelson, and absence of the first pleopod in females.

[5] Janiroidea Sars, 1897 Aselloidea Latreille, 1802 Stenetrioidea Hansen, 1905 Gnathostenetroidoidea Kussakin, 1967