When you think of single-celled organisms, you probably imagine something microscopic. But some of them are surprisingly huge! These giant cells can be seen with the naked eye and challenge what we think we know about biology.
From deep-sea mysteries to slime molds that solve mazes, here are the biggest single-cell organisms on Earth.
1. Caulerpa taxifolia
This invasive green algae looks like a regular plant, but it’s actually one giant cell! It spreads quickly, covering ocean floors and outcompeting other marine life.
2. Valonia ventricosa (Bubble Algae)
Also known as bubble algae, this bright green sphere can grow up to 4 inches wide. It’s one of the largest known single cells and can be found in tropical oceans.
3. Xenophyophores
These deep-sea giants are made of a soft, jelly-like material and can reach several inches in diameter. They thrive in extreme environments, including the deepest trenches of the ocean.
4. Gromia sphaerica
This mysterious organism looks like a rolling mud ball. Found in the deep sea, it moves by leaving behind strange trails on the ocean floor.
5. Acetabularia (Mermaid’s Wineglass)
This delicate, umbrella-shaped algae can grow up to 4 inches tall. Scientists love studying it because its nucleus is located in the stem, proving that even a single cell can have complex structures.
6. Spirostomum
This enormous single-celled protozoan can stretch up to 4 millimeters long. It moves with incredible speed, contracting its body in milliseconds to escape predators.
7. Stentor
Stock photo suggestion: A funnel-shaped microorganism under a microscope.
Often called the “trumpet animalcule,” Stentor is a single-celled organism that can grow up to 2 millimeters long. It has tiny hair-like structures that help it sweep in food.
8. Chaos carolinense
This giant amoeba, also known as the “chaos amoeba,” can reach nearly 5 millimeters in length. It has hundreds of nuclei and constantly changes shape as it moves.
9. Thiomargarita namibiensis
Nicknamed the “sulfur pearl of Namibia,” this bacterium can grow as large as 0.75 millimeters—huge for bacteria! It stores sulfur inside its body, making it appear bright and shiny.
Read More: What is Self-Hypnosis and What Does It Do?
10. Syringammina fragilissima
This deep-sea giant can grow up to 4 inches wide, making it one of the largest single-celled organisms ever discovered. It builds a protective casing around itself, creating a structure that looks like coral.
Read More: Vibrating Molecules May Be The Next Cancer Treatment