Is it a fuzzy sock? An overripe banana? A moldy tube of toothpaste? No! In fact, it’s a humble sea cucumber: a brainless, fleshy form surrounding a digestive tract, and bookended by a mouth and an anus. And while it might look odd, its daily toil paves the way for entire ecosystems to thrive.
How? Sea cucumbers are underwater vacuum cleaners, filtering the sand of algae and waste particles as they ingest it and poop it out. This improves the ocean floor for seagrass beds, corals, and shellfish, and likely fights ocean acidification.
But this cheeky TED-Ed by Cella Wright, titled The Most Important Anus in the Ocean, also reviews the creature’s multipurpose rear end. For example, some sea cucumbers breathe with their anus. Others eat with it. It’s where they reproduce. And still, others expel their regenerative, sometimes toxic guts to surprise and defend against predators.