The scaly-foot snail (also known as the “sea pangolin” or “volcano snail”) is a deep-sea hydrothermal-vent snail. It doesn’t just differ greatly from other marine gastropods, or from other deep-sea gastropods, or from other gastropods in general; it differs greatly from everything.
The species was discovered in 2001, living on the bases of black smokers in the Indian Ocean, and wasn’t properly named until 2015. It lives in the “midnight zone” of the ocean, an abyss darker than the far reaches of our solar system, where the only light comes from the bioluminescence of other animals. To survive down here you need to be your own biome. In this case, that means housing symbiotic gammaproteobacteria in its esophagus. These bacteria subsist on sulfur, and in turn sustain the scaly-foot snail.
i.e., The scaly-foot snail lives on the largesse of bacteria that eat brimstone.
Now about those scales and it’s shell:
They are made of iron. The scales on its foot overlap like roofing tiles, forming a flexible plate-armor.
“Each shell layer appears to contribute to the effectiveness of the snail’s defence in different ways. The middle organic layer appears to absorb mechanical strain and energy generated by a squeezing attack (for example by the claws of a crab), making the shell much tougher. The organic layer also acts to dissipate heat. Features of this composite material are in focus of researchers for possible use in civilian and military protective applications.”“Scaly-foot gastropod” via Wikipedia
These are the only living animal known to use iron in their skeleton. That shell rusts as they age.
They are under two inches, mostly. Those two smooth, pink, forked “cephalic tentacles” aren’t eye-stalks, as they might be on land snails; the scaly-foot snail has no eyes. It has no copulatory organs, either. But it nonetheless has “high fecundity,” as it is a “simultaneous hermaphrodite”—it has both types of sex organs at the same time, and can produce both types of gametes within the same breeding season. If told to go fuck itself, the scaly-foot snail can and will, and won’t take offense.
That might be because it has a bigger heart—relative to its body—then any other animal, around 4% of it’s volume. By comparison, a whale or human heart is closer to 1/4 or 1/3 that proportion.
Let us consider the scaly-foot snail. They—for each of them is most decidedly a they—have iron bones on the outside, and are armored where their cousins are so notoriously gooey. They thrive on brimstone down in the hell-fires bubbling deep beneath everything we know or recognize. They are so little, and so alien, but they’ve got a while lotta love to give.
There’s a lesson here, I’m sure of it—but I’m helpless to articulate it in any clear way, try as I might.