The dominant species in the southern branch belonged to Cypriniformes, while those in the northern branch and the estuarine mouth both belonged to Perciformes.

• 长江南支、北支和口门区水域的种类组成存在一定的差异, 南支常见种以鲤形目鱼类为主, 而北支和口门区以鲈形目鱼类为主。