A " bridge" is a road that goes over water usually, although it could go over dry land, I suppose.

我想，“桥” 通常是一条跨水的道路，尽管它可以跨过旱地。

With sharp spines over its gills, the climbing perch can drag itself over dry lands as it moves from one waterhole to another.

攀鲈的腮部有锋利的脊柱，能拖着自己在干旱的地面上转移，行走于不同的水坑之间。