Another method of sampling posterior kidney is to cut through the translucent swim bladder and retroperitoneal lining and dissect out a piece of the kidney. The kidney lies adjacent and ventral to the backbone.

Cut this sample into two or three smaller pieces prior to putting it into formalin. This will help insure adequate fixation.

The picture to the left is a good representation of what would be seen after the abdomen of the fish is opened and organs are removed. The transparent sac that is running horizontally is the swim bladder.

The video above showed how to cut through the swim bladder in order to gain access to the kidney behind it. The picture to the left is what would be seen after the swim bladder is removed. The kidney is visible and now excisable.