Putting Fishes in Order

Let's look at a diversity of different freshwater fish from different places that were once a part of Gondwana. Examining their relationship to each other can help you tell the story of how Madagascar was connected to other places on earth, and when various populations of fish separated from one another.

Click on one of the taxonomic groups below. When you do, a cladogram will appear showing a group of fish from Madagascar, as well as related fish from other parts of the world. You will then need to drag the fish from their geographic location into their correct location on the cladogram.

Use the sequence of the separation of the different continents to help you determine where to put the fishes in these cladograms.

  • What area shares the most closely related freshwater fish species to Madagascar? What does this tell about continental drift?
  • Why does this analysis work with Madagascar? Would it work to compare North America with Hawai'i? Why or why not?
  • Draw the cladograms in your field notebook. Refer to the timeline and the video showing the separation of Gondwana. Can you hypothesize when the Malagasy and African fishes shared a common ancestor? How about the Malagasy and Indian fishes? Write the dates for these separations where the cladograms branch.