Welcome to MBL March Madness – based on the March Madness NCAA basketball tournament, but instead of basketball teams, beloved MBL organisms went head-to-head in a series of match-ups. By a margin of just 106 votes, the Axolotl (Ambystoma mexicanum) is crowned our inaugural MBL March Madness Champion!
Learn more about your champion!
Check back in 2022 for next year’s bracket!
Four divisions competed for victory:

Lophotrochozoa is one of the major groups within the animal kingdom. It comprises: segmented worms, mollusks (the phylum that includes snails, squid, octopuses, and clams) as well as lophophores, a group of animals that include clam-like organisms known brachiopods and bryozoans, sedentary colony animals sometimes referred to as “moss animals.”

Ecdysozoans are the largest group within the animal kingdom and comprises arthropods (insects, spiders, and crustaceans), as well as nematodes such as roundworms. All organisms in the Ecdysozoan superphylum have an exoskeleton and shed or molt that cuticle layer in order to grow. Unlike the animals in the Deuterosome Division, organisms within Ecdysozoa all develop the mouth first during embryonic development.

While bilaterian animals have a distinct front, back, top, and bottom, non-bilaterian organisms lack that symmetry. Non-bilaterian animals include sponges, jellyfish, corals, comb jellies, sea anemones, and placazoa (simple, free-floating multicellular marine organisms). This group split from bilaterians early in animal evolution.

Deuterostomia may not sound familiar, but it should: you are a deuterostome! Most deuterostomes belong to one of two groups that include most of its members—echinoderms, which includes animals such as the spiny-skinned starfish, sea urchins, and their relatives, and chordates, which include fish and other vertebrates (including humans). The name deuterostome means “mouth second,” because during cell development, the cavity that will become the organism’s anus is formed first by the blastopore, while the mouth is formed secondarily on the opposite side. This is the opposite of the organisms in the Ecdysozoan Division.
We would like to thank all the MBL scientists and staff who assisted us: Caroline Albertin, Elizabeth Baldo, William E. Browne, Karen Echeverri, Kristin Gribble, Roger Hanlon, Marko Horb, Elizabeth Lee, Laurence Anne Lemaire, Michael Levine, Christopher J. Lowe, Mark Q. Martindale, Jennifer McCarthy, B. Duygu Özpolat, James Parente, Nipam H. Patel, David Remsen, Loretta Roberson, and Mayra Sanchez-Garcia.