Scientists discovered three novel Minorisa species

The smallest predatory Marine Picoplankton.


Minorisa is a group of tiny uniflagellates belonging to the Cercozoa. These flagellates are among the most prevalent bacterivorous eukaryotes in coastal marine habitats, and they are the closest heterotrophic cousins of photosynthetic chlorarachniophytes. Since the original description, taxonomy investigations on Minorisa have not been carried out despite their significance for ecology and evolution.

Scientists at the University of Tsukuba have discovered three novel species within the Minorisa genus of marine picoplankton. This discovery improves species identification and our comprehension of Minorisa’s ecological roles in marine habitats by revealing previously unknown diversity.

Scientists isolated five Minorisa strains and performed molecular phylogenetic and microscopic analyses. Utilizing small subunit ribosomal RNA gene sequences for molecular phylogenetic analysis, it was determined that the strains belong to four distinct subclades within Minorisa. Through microscopic examination, it was shown that some strains of Minorisa have an amoeboid stage that lacks flagellum.

Cells have either extrusive or lobose pseudopodia while they are in the amoeboid stage. Scientists updated the description of Minorisa and included descriptions of the three new species: Minorisa fusiformis sp. nov., Minorisa magna sp. nov., and Minorisa megafusiformis sp. nov. These changes were made in light of the phylogenetic analysis and morphological observations.

The diversity that was previously unknown within the genus Minorisa has been made clear by this study. The study’s identified culture strains offer encouraging prospects for delving into Minorisa’s ecological role and learning more about the evolutionary mechanisms behind chloroplast acquisition in chlorarachnion algae.

Journal Reference:

  1. Takashi Shiratori, Yuta Kato, Ken-ichiro Ishida. Molecular and morphological characterization of three novel Minorisa species (Chlorarachnea) and proposal for an emended description of the Minorisa minuta. Phycological research. DOI: 10.1111/pre.12533