Jump fish generally refers to mudskipper. Mudskippers have gills and are true fish, a group of less evolved ancient fish animals. Mudskippers love to run around in the hot sun, so they need to keep their bodies moist at all times or they will die. Their body structure changes very little, and they must regularly immerse their bodies in water. It's not enough to just suck in oxygen by drooling in the mouth, mudskippers need to keep their bodies hydrated regularly to prevent dangerous dehydration. So all mudskipper activities are carried out around the pond.