O'opu akupu is also known as o'opu okuhe (Eleotris sandwicensis). This goby is endemic to Hawaii which means it cannot be found anywhere else except in Hawaii. Its skin is dark brown or black in color. Like all other 'o'opus it has its unique life cycle.

The o'opu akupu can be found in estuaries and lower stream reaches and can grow about 13 inches long. The o'opu akupu can eat invertebrates and small fishes.