How do we get the fish we need?
To get the fish that we need for our study, we have to mate the fish in the following way:
In STEP 1, we mate a female Platyfish with a spotted side pigment pattern to a male Swordtail with no pigment pattern. The little fish that they have are called offspring. All of their offspring have spotted sides.
In STEP 2, we mate one of the male offspring with a spotted side pigment pattern to a female Swordtail with no pigment pattern. Their offspring are the four fish pictured in the diagram at on the bottom of this page. Two of the fish, the heavy spotted and the light spotted, are the fish that we study. These fish have a greater chance of getting a melanoma due to the combination of different genes that they inherit from their parents. 