myzocytosis

traitmech:000631 · CLASS · PROPOSED

A physiological phenotype in which a microbial organism feeds by aspirating prey cell contents through a localized feeding connection rather than engulfing the prey whole.

Trait evidence (3)

DOI:10.3390/microorganisms11081945
Colpodella sp. (ATCC 50594) obtain nutrients by preying on Parabodo caudatus using myzocytosis.

PMID:37630505, PMC10458597. Direct scientific Abstract quote. Main text and actual Figures 7-9 were inspected; Figures 1-6 were not visually audited. Introduction and Conclusions describe aspiration through a feeding channel. Fixed-cell TEM supports prey-membrane uptake at the contact, not direct piercing by the pseudoconoid. Unattached nanoparticle uptake is separate endocytosis, not proof of myzocytosis. Intact prey organelles in food vacuoles do not establish functional organelle retention. Posterior vacuole position and encystation are not universal requirements. The mixed culture does not resolve a complete native protein mechanism.
DOI:10.1111/jeu.13050
cytoplasm contents were transferred through the peduncle to the dinoflagellate.

PMID:39019843, PMC11603288. Direct Nutrition and feeding behavior Results passage, not an abstract quote. Scientific Abstract, culture and fluorescence Methods, feeding Results and Discussion, and actual supplementary Figure S6 with its caption were inspected. S6 identifies imaged SPMC98; the molecular-data isolate SPMC100 is different. Panel D shows deformed cryptophyte material passing through the peduncle; attachment in panel E alone is not ingestion. The organism can also use conventional phagocytosis. Trichocyst discharge may be a fixation artifact, not a demonstrated prey-capture mechanism. Other supplementary figures, molecular datasets and movies were not audited.
DOI:10.1038/ismej.2012.29
parts are sucked out by a microtubule supported feeding tube or peduncle (myzocytosis)

PMID:22513533, PMC3446796. Direct Introduction terminology span, not an abstract quote or independent naming experiment. Main text and actual Figure 2 were inspected; other figures and supplementary movies were not visually audited. Results report Karlodinium armiger tube feeding on copepods and polychaete larvae, so the prey need not be unicellular. Nematode feeding was not directly observed. Abstract and later passages call the strain K-0688, whereas initial Methods and Table 1 say K-0668; no canonical strain is assigned from this conflicting record. Proposed toxin and chemotaxis explanations are not molecular demonstrations.

Provenance

Identifier source: TraitMech local identifier
Definition source: DOI:10.3390/microorganisms11081945

Parent traits (1)

phenotype METPO:1000059

kg-microbe context

No kg-microbe node embedding matched this record in the 2026-04-25 deepwalk.

Canonical examples (1)

Organisms cited as exemplars of this trait. Taxon ids are NCBITaxon and link out to the NCBI record.

Oxytoxum lohmannii NCBITaxon:160603 DOI:10.1111/jeu.13050 Qualified example: imaged SPMC98 feeding on cryptophyte prey, not molecular-data isolate SPMC100. Maintenance cultures Methods at https://doi.org/10.1111/jeu.13050 document natural isolation from the Salish Sea near Anacortes, Washington, in 1993, originally identified as Amphidinium longum. SPMC98 was lost in 2004. Actual supplementary Figure S6 names this strain and shows prey material passing through the peduncle. Feeding mode is prey-dependent; this is not a claim about all isolates or exclusive myzocytosis. NCBI ESearch and EFetch resolved the species and its Amphidinium longum synonym on 2026-10-06.

Discussions and Knowledge Gaps (2)

Open questions attached to this trait. Seeded by just knowledge-gap-scan and curated; see the corpus-wide index.

Reconcile feeding-mode terminology with operational trait boundaries.

CURATION TODO OPEN myzocytosis-feeding-scope-and-parent · raised by codex · 2026-10-06

Not yet attached to a section of this record — a curator sets attaches_to (e.g. causal_graphs#some_edge) so the gap shows beside the mechanism it concerns.

This is an organismal feeding phenotype, not a peduncle, pseudoconoid or sequence feature. The 2023 Discussion calls myzocytosis a form of apical phagotrophy and endocytosis while arguing against phagocytosis and trogocytosis in its studied system. The 2012 Introduction uses phagocytise for feeding-tube uptake; the 2024 study contrasts myzocytosis with conventional whole-prey phagocytosis. Those usages are not silently treated as identical. Local phagocytosis traitmech:000627 requires particle enclosure and internalization; phagotrophy traitmech:000628 requires particulate ingestion and nutrient assimilation. Retain phenotype METPO:1000059 pending a closer feeding-mode hierarchy rather than assert unsupported universal subtyping. Mere attachment, free-particle uptake, extracellular digestion or an apparatus-like sequence does not establish prey-content aspiration. A microbe may use several feeding modes; these possession traits are not declared disjoint. No unverified synonym or xref is asserted. Prey death, mechanical piercing and a particular vacuole position are not definition requirements.

Separate observed aspiration from inferred apparatus and protein functions.

KNOWLEDGE GAP OPEN myzocytosis-native-feeding-mechanism · raised by codex · 2026-10-06

Not yet attached to a section of this record — a curator sets attaches_to (e.g. causal_graphs#some_edge) so the gap shows beside the mechanism it concerns.

Fixed-cell contact ultrastructure does not establish every step by continuous observation. The 2023 paper cites earlier cytochalasin experiments; those experiments were not independently audited here. Its CellMask staining description alone is not accepted as proof of a specific actin mechanism. The 2024 molecular data are from a different isolate than the feeding micrographs, and trichocyst-mediated capture remains uncertain. The 2012 study did not measure the proposed toxin. Obtain taxon-paired functional evidence before adding protein accessions or a causal graph. Ancestral feeding and apicomplexan invasion similarities are hypotheses, not proof of one universal apparatus or molecular mechanism.

Curation history

2026-10-06T00:46:04Z · MINTED_TRAITMECH_ID · codex
Added myzocytosis with three DOI-backed snippets and a natural, strain-qualified Oxytoxum example. Ignored-and-hidden searches and pinned METPO review found no exact record. Reserved METPO:1058400 in v507. Distinguished prey-content aspiration from whole-prey engulfment, free-particle uptake and sequence interpretation; retained hierarchy and mechanism gaps.