Answer: External
Step-by-step explanation:
The salmon is a fish species which reproduce by external fertilization. External fertilization is a process of fertilization of male and female gametes outside the body of the female mate. This is used by the aquatic species as a mode of reproduction.
In the case of salmon the female release the eggs at the bottom of the water body and the males release sperms over them. This way the eggs get fertilized by the sperms through the process of external fertilization.