Paramoebidiidae[1] is a family of single-celled eukaryotes, previously thought to be zygomycete fungi belonging to the class Trichomycetes,[2] but molecular phylogenetic analyses place the family with the opisthokont group Mesomycetozoea[3] (= Ichthyosporea[4]).

The family was originally called Amoebidiaceae, and considered the sole family of the fungal order Amoebidiales that included two genera, Amoebidium and Paramoebidium.

[2] However, Paramoebidium is now the sole genus of the family Paramoebidiidae and Amoebidiidae is likewise monogeneric as it was recently emended to include only Amoebidium.

[1] Species of Paramoebidium are obligate symbionts of immature freshwater-dwelling arthropod hosts such as mayfly and stonefly nymphs and black fly larvae.

Paramoebidium species attach to the digestive tract lining of their host via a secreted holdfast.