How do scientists document and study the most diverse vertebrate group on Earth?

What, exactly, is a fish? Find out why that’s not a simple question, and how ichthyologists determine how to classify members of the largest and most diverse of all vertebrate groups. Drawing on evolution, ecosystem diversity, and biogeography, this six-week online course follows Museum scientists into the lab to investigate whether a specimen is a new species of South American catfish.

Course cost: $549. 3 graduate credits available at an additional cost. For more information, visit http://www.amnh.org/learn/fishes