Ancoracysta is a genus of eukaryotic microbes containing the species Ancoracysta twista, a predatory protist that appears to be related to Haptista.[1]

Scientific classification Edit this classification
Domain: Eukaryota
Clade: Diaphoretickes
Clade: Provora
Phylum: Nebulidia
Class: Nebulidea
Order: Nebulidida
Family: Nebulidae
Genus: Ancoracysta
A. twista
Binomial name
Ancoracysta twista
Janouškovec, Tikhonenkov, Burki, Howe, Rohwer, Mylnikov & Keeling 2017[1]



Ancoracysta twista was first described in November 2017 in Current Biology. It was found in a sample collected from the surface of a tropical aquarium brain coral. It actively feeds on Procryptobia sorokini, probably immobilising its prey through discharging a previously unknown type of extrusome named an ancoracyst.[1]

Genetic analysis shows that it is not closely related to any known lineage, but it may be most closely related to a grouping of haptophytes and centrohelids (Haptista). It is notable for having a gene-rich mitochondrial genome, the largest known outside the jakobids or Diphylleia rotans. Uniquely, it appears to contain both the nucleus-encoded holocytochrome c synthase system III and the mitochondrion-encoded bacterial cytochrome c maturation system I.[1]



A 2018 study from Cavalier-Smith, Chao & Lewis created a new subphylum and subsequent lower taxonomic ranks for Ancoracysta twista. They also created a new combination for Colponema marisrubri (Mylnikov & Tikhonenkov, 2009), which was shown to be ultrastructurally similar and phylogenetically close to A. twista, thus renaming it A. marisrubri.[2]

A 2022 study placed A. twista in a new supergroup Provora, closely related to other supergroups of Diaphoretickes such as Haptista, but no longer within Haptista.[3]


  1. ^ a b c d Janouškovec J, Tikhonenkov DV, Burki F, Howe AT, Rohwer FL, Mylnikov AP, Keeling PJ. "A New Lineage of Eukaryotes Illuminates Early Mitochondrial Genome Reduction", Current Biology 2017, doi:10.1016/j.cub.2017.10.051
  2. ^ a b Cavalier-Smith, T.; Chao, E. E.; Lewis, R. (17 April 2018), "Multigene phylogeny and cell evolution of chromist infrakingdom Rhizaria: contrasting cell organisation of sister phyla Cercozoa and Retaria", Protoplasma, 255 (5): 1517–1574, doi:10.1007/s00709-018-1241-1, PMC 6133090, PMID 29666938
  3. ^ Tikhonenkov, Denis V.; Mikhailov, Kirill V.; Gawryluk, Ryan M. R.; Belyaev, Artem O.; Mathur, Varsha; Karpov, Sergey A.; Zagumyonnyi, Dmitry G.; Borodina, Anastasia S.; Prokina, Kristina I.; Mylnikov, Alexander P.; Aleoshin, Vladimir V.; Keeling, Patrick J. (2022). "Microbial predators form a new supergroup of eukaryotes". Nature. 612 (7941): 714–719. Bibcode:2022Natur.612..714T. doi:10.1038/s41586-022-05511-5. PMID 36477531. S2CID 254436650.