nematodes

Nematodes are the most abundant multicellular lifeforms on earth.

They have successfully adapted to nearly every niche, from marine to fresh water, from the polar regions to the tropics, as well as the highest to the lowest of elevations.

They represent, for example, 90% of all life on the seafloor.

Though 20,000 species have been classified, it is estimated that this number might be upwards of 500,000 if all were known.