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Raising Horseshoe Crabs in My Classroom

by
Bill Whorton

Horseshoe crabs, as a species, have lived for over 500 million years! I often remind myself of that fact while observing the months-old horseshoe crabs my students and I are raising in our classroom. Each school day, we’re able to witness a living fossil, and we’re helping insure that future generations can, too.

Several years ago, I was looking to offer more hands-on learning experiences to my fifth-grade science students. Our school is a short distance away from the Chesapeake Bay, but we do very little to experience and learn from this tremendous resource. In the course of researching possible field trips, I discovered that the Maryland Department of Natural Resources (D.N.R.) had a program allowing teachers to raise horseshoe crabs in their classrooms. At the time, I didn’t know much about horseshoe crabs, other than that I would occasionally see their awkward-looking shells on the beach. However, raising an animal from the Bay was the type of hands-on experience I was looking to provide my students with, so I signed up. Three years and over 60 successfully-raised crabs later, I am extremely grateful and proud to be part of a program that allows my students and me to learn about and protect this valuable natural resource.

Atlantic horseshoe crabs come ashore in late spring to spawn on Atlantic coast beaches, including those within the Chesapeake Bay. During this time, female horseshoe crabs lay thousands of eggs. The Maryland D.N.R. collects some of these eggs and distributes several hundred of them to each participant of its Horseshoe Crabs in the Classroom program. Participants attempt to raise the eggs into healthy juvenile horseshoe crabs that can be released back into the waters of the Bay the following spring.

Each year, for the past three years, I’ve collected eggs from the D.N.R. and brought them to tanks in my classroom. I monitor the crabs throughout the summer as they hatch, test their water quality, and feed them. By the time students arrive in September, juvenile horseshoe crabs are “swimming” throughout the tanks. A colleague of mine, Chris Brown, and I meet with students once a week during recess throughout the school year to learn about horseshoe crabs and to test the water quality of the tanks. Using guest speakers, hands-on demonstrations, and research, students learn about the history, habitat, anatomy, challenges, benefits, and life cycle of horseshoe crabs. They learn that horseshoe crabs help save human lives and that other species depend on them for survival, as well. The learning experience culminates with the exciting release of the raised crabs back into the Chesapeake Bay each May during a D.N.R. sponsored release event.

We have horseshoe crabs throughout four tanks in our school. Tank 1 contains three crabs from my first year (2009) with the program. We didn’t release these crabs that year because they were very small compared to their siblings, two of them were missing tails, and one of them was even missing some legs. However, after numerous molts, or shedding of their shells, the crabs have all of their legs and tails accounted for. The largest of these crabs, or Sandy, as my students call it, measures about five inches from front to tail tip. Tanks 2 and 3 contain several juvenile crabs that hatched last summer. These “baby” crabs are no bigger than the end of an eraser on a pencil. Tank 4 contains eighteen crabs that hatched in the summer of 2010, and they range in size from the diameter of a dime to the diameter of a fifty-cent piece. Most of these crabs will be put back into the Chesapeake Bay this May to join the twenty-nine other horseshoe crabs that we’ve already released.

I’ve gained a lot from raising horseshoe crabs in my classroom, including learning to appreciate and respect them. Of course, I’ve learned how to care for them, but they don’t really need much from me. After all, they’ve been at this for longer than people have. Most of my time is spent enjoying them and admiring how unique they are. I enjoy the way that the three-year old crabs come out to “greet” me when I turn the lights on each morning. I like watching them make patterns in the sand, including flattening out areas that I’ve disturbed. I’m fascinated at how two of the three-year-olds re-grew legs and tails, but most of all, I’m in awe that a creature can be so simple and yet so amazing.

Additional Resources:

  • Additional information about my school’s program can be found at our website.
  • Information on the Maryland D.N.R. Raising Horseshoe Crabs in the Classroom program is available here.
  • A great Nature video clip from “Crash: A Tale of Two Species” about the plight of the horseshoe crab and a little bird called the red knot is available here.
  • A free teachers guide to accompany the “Crash: A Tale of Two Species” video is available here.