When you think “cells” you generally also think “microscopic”, but sometimes evolution likes to take things in a different direction. It’s hard to believe from looking at it, but this green alga, Caulerpa taxifolia is an organism composed of one single cell – the biggest one on the planet.
Also known by the sinister moniker “killer alga”, these feathery green fronds are native to warm tropical waters in areas like the Caribbean coast, the Gulf of Guinea, and the northern Indian Ocean. Its vibrant color attracted
It’s now considered an
Since then, it has expanded its range far across the seabed, where it causes
C. taxifolia was also discovered off the coast of southern California in 2000, and it took a concerted effort from authorities over six years to eradicate it from the area.
As well as being able to grow quickly and withstand cooler waters, the aquarium strain of C. taxifolia can achieve impressive sizes, with primary fronds sometimes reaching as far as 60-80 centimeters (24-31 inches) in the depths. And yet, it is still a single-celled organism. How is this possible?
It’s all down to some very elegant organization. C. taxifolia, along with other similar siphonous algae, is an example of a coenocytic organism. Coenocytes contain
As the authors of a
The killer alga is not the only peculiar underwater resident that takes advantage of this arrangement. Check out the intriguing Ventricaria ventricosa, also known as bubble algae, sea grapes, or
Like C. taxifolia, V. ventricosa is
Reaching diameters of up to 9 centimeters (3.5 inches), it can’t quite compete with C. taxifolia for world’s largest single-celled organism, but it would certainly win an “algae masquerading as fruit” costume contest. So, that’s something.