Tuberomeba capitovia gen. et sp. nov. (Amoebozoa, Tubulinea) accommodates an incertae sedis lineage of monotactic, fish-associated amoebae.

A new species from a yet undescribed group of small monotactic amoebae was isolated from a cage with farmed rainbow trout (Oncorhynchus mykiss). Artificial salinization of the original water sample to 18‰ was required to recognize and isolate this amoeba, whereas in cultures with a salinity level corresponding to freshwater, the amoebae were in an encysted state. The studied amoeba is closely related to the clade of strains isolated from the internal tissues of various fish: the liver of tench (Tinca tinca), the liver of carp (Cyprinus carpio), and the kidney of freshwater stinging catfish (Heteropneustes fossilis) in the Czech Republic. Members of this clade were never described taxonomically. Based on the integrative approach, this clade is described as a new genus of Tubulinea, Tuberomeba gen. nov., while the studied isolate is described as a new species, T. capitovia sp. nov.