Heliorapha

It is classified within a monotypic family Helioraphidae inside the actinophryids, a group of heliozoa that belong to the Ochrophyta along with other protists such as diatoms and brown algae.

[1] Heliorapha azurina is a heliozoan, a unicellular protist with tapering arms called axopodia sustained by axonemes.

[2] Heliorapha azurina is a heterotrophic flagellate exclusively found in tropical climates, in both marine and terrestrial habitats.

[2] The species differs from Ciliophrys by the presence of tapering axopodia that are too broad at the base to be sustained solely by a triad of microtubules, a characteristic of Pedinellales.

This incorrect assignment to the Pedinellales was approached in 2013, when protozoologist Thomas Cavalier-Smith moved the species to its own genus Heliorapha and family Helioraphidae.