A single-celled organism so massive it is visible to the naked eye

Nature · Published 29 September 2026 Swipe more like this →

In short: Most microscopic life remains hidden, but some single-celled organisms defy expectations by growing large enough to see without a microscope. This video examines a unique specimen discovered in a marine tank, exploring why certain microorganisms reach such unusual proportions.

The organism was discovered by James, who manages the marine tanks for the Journey to the Microcosmos project. While cleaning, he spotted the creature due to its distinct bright red color and significant physical size.

This observation highlights the surprising scale some single-celled life can achieve, challenging the common assumption that all microorganisms are invisible to the unaided eye.

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