Genus Rhizonema

Females. No cyst stage. Body globose with prominent neck and terminal cone. Cuticle thick, wavy; entire body annulated, except terminal cone. D-layer absent. No subcrystalline layer. Vulva and anus situated on terminal cone having a thickened cuticle. Phasmids not observed. Eggs retained in female body together with hatched second stage juveniles.

Males. Body twisted. Lateral field with four lines. Spicules nearly straight, pointed, posteriorly directed. Cloacal tubus well developed. No Phasmids.

Juveniles 2nd stage. Lateral field with four lines. Oesophageal glands filling body cavity. Tail conical pointed with long hyaline terminal part. Phasmids with lens-like structure.