Once the dry season arrives and the water shortage shrinking, this fish, that can only grow to 7.5 inch size, sometime is trapped in the hollow trunk of the tree made of insects, coconut, and even tin cans. They live huddled in a dirt hole and breathe using the skin rather than gills.
Unlike most fish that breathe with gills, rivulus mangrove breathing using skin. When the habitat begins to dry, they are hiding in holes in the ground, or even a coconut shell drink cans. In hiding, the fish breathe with the skin and can live for months without water. After the rain came and water flood the habitat back, they came out from hiding and live like ordinary fish.