Monterey Dorid

Fascinating facts about the Monterey Dorid

• This sea slug breathes through a ring of feathery gills on its back — but only when it's not being attacked. The moment a predator touches it, the gills retract into a pocket faster than you can blink, a defensive reflex so reliable that researchers use it to test whether the animal is still alive.
• It eats toxic sponges that would poison most animals, then stores their chemical defences in its own skin as a shield against predators. Scientists call this 'sequestration' — the slug becomes toxic by eating toxins, turning its dinner into armour. Other nudibranchs do this too, but Monterey dorids are masters at processing compounds that dissolve in water, not fat.
• A Monterey dorid is hermaphrodite and can produce eggs at any time of year, yet it refuses to mate with itself. During mating, two slugs line up side by side and exchange sperm packets in a ritual that can last hours. They're so committed to outbreeding that they've evolved to reject their own genetic material even when no partner is available.
• Its orange-red body is studded with papillae — finger-like projections that aren't just for show. Each one is loaded with sensory cells that detect chemicals in the water, letting the slug hunt sponges in the murk of the deep reef by taste alone. At depths of 10 to 50 metres, vision is useless; taste is survival.
• The Monterey dorid grows to just 8 centimetres long yet produces egg ribbons that spiral around rocks in intricate designs — each ribbon containing thousands of microscopic larvae. A single adult can lay enough eggs in its lifetime to cover a boulder. Most larvae die, but the ones that find the right sponge species begin their own chemical-sequestering lives.

At a glance

About the Monterey Dorid

In the dimly lit recesses of the Pacific coastline, the Monterey Dorid navigates its domain with a quiet purpose, its undulating body gliding effortlessly across the rocky substrate as it searches for unsuspecting sponges and hydroids to devour. With a mottled brown and orange hue that blends seamlessly into the surrounding landscape, this master of disguise weaves in and out of the shadows, its very existence a testament to the intricate beauty of the ocean's twilight zone. As it moves, the delicate tendrils of its rhinophores tremble with an almost imperceptible sensitivity, drinking in the subtlest whispers of its underwater world.

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