Sea Urchins: A Spiky Story of Survival

Ladies and gentlemen, gather ’round for the extraordinary tale of the sea urchin — a creature that’s not only alive when you’re eating it but sometimes still waving hello (or goodbye) with its spines. Gross? Perhaps. Fascinating? Undeniably. Let’s dive into the undersea escapades of this spiny little wonder and why its survival matters.

Alien Invaders of the Ocean? Not Quite.

When sea urchins hatch, they look like tiny lunar landers zipping across the ocean. These larvae, resembling miniature spaceships, grow a juvenile sea urchin body inside their translucent forms. Think of it as a live-action science experiment with a splash of Pixar magic.

As they mature, sea urchins develop into gonochoristic creatures, meaning their five gonads are either testes or ovaries. Occasionally, there’s a wildcard like the purple sea urchin (Strongylocentrotus purpuratus), which can show hermaphroditism. No brain, no heart, but hey, they’ve got surprises.

The Culinary Quandary

For those who enjoy the delicacy known as uni (that’s sea urchin gonads, for the uninitiated), here’s a fun fact: it contains anandamide, the same euphoria-inducing chemical found in cannabis. Who knew your sushi could double as a mood booster?

But before you dive into your sashimi, remember: the sea urchin’s movement postmortem isn’t a sign of rebellion. It’s just its spines and tube feet, powered by cellular energy, dancing one last jig before the lights go out.

Brains? Who Needs ’Em?

Sea urchins don’t have brains or hearts. Instead, they use a hydraulic water vascular system to move, eat, and breathe. Their tube feet — tiny appendages equipped with suction cups — and their spines work in harmony, allowing them to glide along the ocean floor.

Despite their lack of central neural control, these creatures are remarkably perceptive. Photoreceptor cells in their tube feet allow them to respond to light and visual stimuli. They might not ace an IQ test, but they’re doing just fine for spineless, brainless wonders.

The Guardians of Coral Reefs

Sea urchins aren’t just sushi stars; they’re also ecological superheroes. Grazing on algae, they prevent these fast-growing plants from smothering coral reefs. By creating space for coral larvae to settle, they play a crucial role in maintaining reef health.

But trouble is brewing beneath the waves. A microscopic parasite, Philaster apodigitiformis, is wiping out sea urchin populations in alarming numbers. In 2022, the long-spined sea urchin (Diadema antillarum) suffered devastating losses in St. Thomas due to this parasite, which swarms their bodies and spines, effectively eating them alive.

Why Should You Care?

No sea urchins mean more algae. More algae mean fewer thriving coral reefs. And fewer coral reefs mean trouble for marine biodiversity. While researchers are working tirelessly to establish broodstock populations to combat this crisis, there’s no cure or vaccine yet.

Without our spiky friends, the ocean’s delicate balance could collapse, leaving us with barren, algae-covered wastelands. And let’s face it, nobody wants that — not even the urchins.

The Takeaway

So, the next time you spot a sea urchin on your plate or in the ocean, give it a moment of respect. Whether it’s wiggling its spines or guarding a coral reef, this oddball creature deserves our admiration and protection. After all, it’s not every day you meet an animal that can move without a brain, taste like euphoria, and save the ocean at the same time.

Here’s to the sea urchin — a spiny miracle worth saving.

Inspired by Barry Took, co-created with Copilot