Mudfish are fish that found ways to breathe when water through their gills was not enough. They adapt as we must all.
Mini Finny
This fish did not take the easy path in life and advises you do the same. It dwells in deep, thick clay that few would be able to move in, let alone breathe. In fact, the only way it is able to do so is by virtue of its miniscule size. The clay it lives in is highly prized in pottery circles but the Finny is so hardy (and small) it can survive being worked into a dish, glazed and fired. It will then happily sip on whatever the dish holds. Feed it well.
Glibfin
Mudfish are not all closely related. They have simply developed similar survival traits. They will breathe what they must. Mudfish will use a gill, a lung, breathe through their skin or invent some other way to keep going. Or perhaps not breathe at all. Such is the claim of the glibfin who says that it lives on a higher purpose. Of course, it won’t say what that is. Regardless of what it breathes in, it exhales smugness.
Pisces
While these two fish are famous as a constellation, they are well known to astrobiologists for being respiratorially self-contained. What one exhales the other breathes in. Then what that one breathes out the first inhales. In a breathy loop forever. This is an effective strategy in the emptiness of space. Were they born as two together? Is it just one single organism tricking us to believe it’s two? In which case, it would still be confusingly miraculous. Tricky thing, life. When you’re made of suns perhaps life just has to be.
Glomhead
It’s not often we think about breathing and when we do it doesn’t always help. This fish thought about it and decided to breathe your air. If you find yourself gasping all of a sudden for seemingly no reason, consider either aggressively fishing the area or leaving immediately. Yeah, that’s what it is. We’re not just out of shape.
Fool’s Goldfish
Inhales gold flakes found in the mud, exhales fool’s gold. High status to have one in your court. Has bankrupted kingdoms.
Grubble Kippers
A rare summer hibernator, it’s also a more common winter hibernator. It really just seems to mostly sleep. Does not appear to breathe at all. Is it dead? It claims to live but has never been observed doing much of anything.
Jellyfish
Jellyfish are not really fish. Are they jelly? Do they breathe? You explain them.
Lava Loach
Born in embers, the lava loach initially gasps down sparks to survive. As it grows it breathes in full flames. Few make it to adulthood but those that do burrow deep to swim magma rivers. The most ancient one sits at the Earth’s center. If there ever was a devil below, the oldest lava loach gulped him down.