The morphology and small subunit rDNA gene phylogeny of the novel goniomonad genus Ebisugoniomonas and two novel Poseidogoniomonas species

Goniomonads are heterotrophic representatives of Cryptista, sister lineage to the phototrophic Cryptists. Goniomonads are morphologically and genetically diverse, comprising nine genera described so far. Besides morphologically described genera, SSU rDNA sequencing data has revealed the existence of at least one more monophyletic genus-level lineage within goniomonads, as well as more novel species within the described genera. Furthermore, the diversity of SSU rDNA sequences within goniomonads is not fully investigated, and addition of novel sequences can be crucial for understanding the evolution and diversity of goniomonads and for providing a basis for taxonomic descriptions. The morphological data record available for goniomonads is relatively limited: many cellular features remain undescribed, or described only for a few isolates.

In this study, we describe the new genus and species Ebisugoniomonas hispanica n. gen. n. sp., and two novel species within Poseidogoniomonas : P. posteriocircus n. sp. and P. zopfkaesiformis n. sp. We report a range of observations on the cellular features of goniomonads: periplast plate arrangement pattern and intracellular structures. We also update the SSU rDNA phylogeny of goniomonads by adding sequences from novel isolates and environmental DNA studies.

Several sequences recovered from novel isolates and environmental DNA datasets likely represent highly divergent lineages of goniomonads in the SSU rDNA phylogeny.