One thing I found unrealistic (I know it's not a 100% serious movie hah)

But everyone seemed to know exactly what a piranha looked like! Haha (in the sequel too, but that's beside the point) Every single person, it wasn't just "is that a fish? that's a weird fish" "oh my god it's a killer fish!" everyone was "is that a piranha?" "oh my god! that's a piranha!" somehow, some way, everyone except me knows specifically what a piranha looks like ....