Compare And Contrast The Developmental Stages Of Salmon

The structure of the mouth of the Atlantic salmon in all its developmental stages also allows it to successfully adapt to these two environments. Generally in the fresh water phase (and this encompasses all the stages prior to smolting), young salmon eat insects, invertebrates and plankton, while adult salmons in salt water eat other fish, squid, eels, and shrimp (Quinn, 2005). This makes the structure of the mouth of the salmon develop differently at each stage to parallel their diet. In stages before smolting salmon usually have invisible teeth which are able to appropriately match their fresh water diet as they are relatively smaller at this point. In smolting fish on the other hand, visible teeth begin to emerge from the gums and the dorsal surface of tongue pointing to the back of the mouth. Long teeth appear on the dorsal surface of tongue (Ackerman, 2017). These teeth prepare the salmon for a change in diet. The change that occurs with the salmon’s teeth therefore better equip it for the change from feeding on smaller food …show more content…
There is a difference in the levels of Na+/K+ ATPase that exist in the intestine in salt water and in fresh water. During the developmental stages of the salmon that take place in fresh water, the intestine has decreased levels of Na+/K+ ATPase to suit the fresh water environment. The opposite happens when the salmon migrates to salt water. In order to adapt to the new environment of high salinity levels, Na+/K+ ATPase increases. This enzyme elevates the amount of Na+ actively transported out of the intestine in exchange for potassium which is required in high levels within the cell. The action is similar to that of the chloride cells. As a permeable surface and tissue, the intestine increases its water absorption properties to suit the salt water environment (Ackerman,