A few years ago when one of my 2nd grade reading groups was reading Sharks by Gail Gibbons, I said, “Wouldn’t it be fun to get an up-close, personal look at a real shark?”
Since we live far from an ocean or aquarium, we ordered a spiny dogfish shark specimen and dissected it. Every year since, my class has begged, “When are we going to dissect a shark?” Shark dissection has become an annual ritual.
Read on to find out what we did.
I ordered a spiny dogfish shark from a biological supply company, Carolina Biological Supply. Carolina sells specimens, dissecting kits, and dissection manuals. Since a double-injected spiny dogfish shark costs $13.25, I purchase one shark and work with young scientists in small groups while I dissect.
The specimen we get is a 22" to 27" spiny dogfish shark. For about $3.00 extra, we get a “double,” a shark that has blood vessels double injected with latex, red for arteries and blue for veins. Last year I ordered a pregnant female shark with five pups, which made for even more interesting conversations.
A dissecting kit is nice have, though not essential. You could use a pair of sharp, pointy scissors and a knife. I like to have a dissecting kit because the tools make the dissection more special and scientific.
Students usually ask to see the brain. If you’re careful, you can open the skull and find not only the brain, but the optic nerve. I wasn’t able to do this the first year, but my clumsy scissor work has improved since then.
Here are things to look for with your students:
- Multiple rows of teeth
- Tiny sensory holes in skin
- Brain and optic nerve
- Gill slits and gills
- Heart and circulatory system
- Stomach and intestines (including contents)
- Liver, pancreas, and spleen
Latex gloves are a good idea for students and teacher. Students may remove their gloves to touch the shark’s skin and feel the denticles — sandpaper-like skin made up of tiny teeth/scales — but most of the time, you’ll want young scientists to wear gloves. We had paper doctor masks available and some students chose to wear them, mostly because of the smell of preservatives. Ask your school nurse for a box of gloves.
To organize your class, divide into groups of five or six and call small groups to your lab table to see part of the dissection. All students will get to see part of the dissection and can return to see the specimen while they draw. Those who are waiting either read books about sharks or work on their dissection sketches.
Sketches — Cut white construction paper into 6" X 18" pieces and give each student two pieces of paper. Ask students to sketch and label with pencil and later trace pencil lines with a Sharpie or Flair pen. Students sketch and label the outside of the shark on Day 1. On Day 2, students sketch and label interior organs on a second sheet of paper.
Doing the actual shark dissection on Day 2 builds excitement. It also gives students a chance to get familiar with the specimen. Students may need reminders about acting like scientists and not saying “EWW!” or “Yuck!” No one is forced to witness a dissection, but almost all, if not all, students are curious and want to participate.
- Use a roasting pan to contain the shark.
- Keep shark refrigerated in a plastic bag when you are not working with it.
- Rinse shark first to remove preservatives.
- Take your time. Don’t rush the dissection.
- Check to make sure students’ sketches are accurate.
- Create a bulletin board display of the sketches.
Book Display — Set up a shark books display and encourage students to read about sharks.
Paintings — Students show what they know through art.
What’s the probability of a shark attack? Check it out!