How to name a Chytrid: the identification and characterisation of an unknown marine Chytrid.

The identification and characterisation of marine Chytrids has long been considered a grey area of marine fungi understanding, with hazy knowledge linking function and taxonomy.

Garvetto et al. (2019) investigated the morphology, global distribution and phylogeny of an unknown Chytrid infecting the marine Diatom Skeletonema. By collecting and isolating the Chytrid from Skeletonema, the study used a combination of microscopy and molecular tools (Phylogenetic tree construction and Metabarcoding), followed by accessing Ocean sampling day (OSD) data.

Microscopy revealed a zoospore thallus and observations of mature sporangia cell wall thickening, characteristic of the order Rhizophydiales morphology. Phylogeny supported microscopy observations as the unknown Chytrid belongs to the Rhizophydiales. Yet the Chytrid didn’t belong to either family of the order, thus giving the temporary name SKCyt. In terms of distribution, Metabarcoding and OSD data identified similar isolates distributed on each North Atlantic coastline.

In summary, this paper gives an example of what molecular and microscopy tool combinations can achieve, contributing to our understanding of marine Chytrid morphology, distribution and taxonomy. However, this paper leaves you with little discussion into SKCyt’s form and function. For future studies I would suggest further investigations into form, function and interactions of SKCyt and other unknown Chytrids.

Garvetto, A., Badis, Y., Perrineau, M. M., Rad-Menéndez, C., Bresnan, E., & Gachon, C. M. (2019). Chytrid infecting the bloom-forming marine diatom Skeletonema sp.: Morphology, phylogeny and distribution of a novel species within the Rhizophydiales. Fungal biology, 123(6), 471-480.