7. Blob Fish
https://imgur.com/gallery/oRh1zxh Psychrolutes marcidus. Next up we have a fish only a mother could love. The blob fish is so named because, well, it looks like a blob. But this appearance is out of context and, in the water, the blob fish looks slightly better. Most fish float using a swim bladder, an internal organ which is filled with gas. The gas inside their bodies balances against their relative weight, stopping them from sinking and stopping them from expending energy to keep afloat. Think about when youre swimming. Its harder to dive down when youve just taken a big lungful of air right? Same reason. But at depth, the gas would be desperate to escape to the surface, making it a liability. So instead blob fish have evolved a gelatinous covering which helps them achieve the same outcome. A similar adaptation is found in cartilaginous fish such as sharks, but they have a super oily liver rather the fun features of the blob fish. So when living at the depths they do, this covering is perfectly adapted to let them stay buoyant without shooting to the surface. Unfortunately for the blob fish, this unique adaptation also means that when they're taken out of that environment, and because they lack any major skeleton structure, they kind of collapse and look like a doll that's been dropped in the fire. But then I suppose we shouldnt laugh. If the roles were reversed and we were suddenly made to live at the depths that they happily do, wed be crushed to about a fifth our normal size and just be a blob as well.