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Limits RegistryThiomargarita magnifica, discovered in Guadeloupe mangroves and described in 2022, forms single bacterial cells up to about 2 cm long — roughly 5,000 times larger than typical bacteria and visible to the naked eye as thread-like filaments, forcing a reconsideration of assumed size limits for prokaryotic cells.
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Thiomargarita magnifica, discovered in Guadeloupe mangroves and described in 2022, forms single bacterial cells up to about 2 cm long — roughly 5,000 times larger than typical bacteria and visible to the naked eye as thread-like filaments, forcing a reconsideration of assumed size limits for prokaryotic cells.
The longest single bacterial cell documented in peer-reviewed literature, distinguishing it from the largest single-celled organism overall (already catalogued separately as a eukaryotic alga), and confirmed as visible without magnification.
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Permanent ID limitsregistry.com/limits/LR-LARGEST-KNOWN-BACTERIUM-VISIBLE-NAKED-EYE
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Limits Registry. LR-LARGEST-KNOWN-BACTERIUM-VISIBLE-NAKED-EYE. Largest known bacterium, visible to the naked eye. 2026.