Le fishe on mountains(???)

So im playing with my friend now, and when i ended with some routine food crafting, i step out of main hall and see THIS. We even dont try to fishing, so i have one question. What the actual fuck did this fish forgot on our base in MOUNTAINS?????

So im playing with my friend now, and when i ended with some routine food crafting, i step out of main hall and see THIS. We even dont try to fishing, so i have one question. What the actual fuck did this fish forgot on our base in MOUNTAINS?????