Suborder CYMOTHOIDA Wägele, 1989
Introduction
The Cymothoida include those families of the former Flabellifera that are scavengers, ectoparasites, blood-sucker or predators (Dreyer & Wägele 2001). Primitively, the group has evolved from the scavenging and predatory feeding strategy towards parasitism on fish and other Crustacea. In the most basal families (e.g. Cirolanidae) the mandibular molar is an articulating toothed blade. This structure and the whole mandible is variously modified and reduced to a more piercing structure in the more parasitic families.
While it is possible to place some families into larger monophyletic groups (former suborders into superfamilies) the remainder are lumped here for the time being in a polyphyletic superfamily Cymothoidea.
Diagnosis
Mandible incisor multidentate; lacinia mobilis absent; spine row a lobe with row of independent short simple spines; molar blade-like, with curved row of denticles along distal margin (or mandible variously reduced from this condition); uropodal rami ventral to pleotelson, articulating from side to side in vertical axis inside branchial space; pleotelson underside flat, without ventrolateral ridges (pleopods not enclosed laterally); pleopods 1–5 similar.
References
Dreyer, H. & Wägele, J.-W. 2001. Parasites of crustaceans (Isopoda: Bopyridae) evolved from fish parasites: molecular and morphological evidence. Zoology (Jena) 103: 157–178
Wägele, J.W. 1989. Evolution und phylogenetisches System der Isopoda. Stand der Forschung und neue Erkenntnisse. Zoologica (Stuttgart) 140: 1–262