The Biogeek Memoirs: Goldfish

I know, I know. You were hoping for something a little on the wild side like, maybe, pronghorn antelope, and here I am writing about… goldfish. Hey, goldfish are kind of cool, and I have a lot of fun memories about them.

My first goldfish tank was delivered to my house by my mom as a gift for my oldest son. That tank led to another in time, and then classroom fish tanks, and finally a huge tank in my family room. Goldfish are great. Goldfish are the stuff of science if you are an intrepid biology teacher who can deal with the chaos and squeals in your classroom.

I had a large tank towards the front of my classroom that housed a variety of goldfish.

I kept a few fancy goldfish in the classroom tank, and during the year new fish would get dumped in because they were short term visitors destined to do science with the kids. The new fish were usually cheap feeder fish sold by pet stores as food for turtles, snakes, and other hungry critters. These lucky guys hit the jackpot since they got to do science!

Goldfish are cold blooded critters, so their need for oxygen is determined by their environment. If the water is warm, the fish need more oxygen. If the water is cold, they need less oxygen. Oxygen use reflects the rate of biochemical reactions in living things; determining how fast the fish is “breathing” in different water temperatures can reveal the relationship in the fish between the water temperature and how fast it can do its body chemistry to produce energy. This lab was a riot as the kids handled the fish, ice cubes, warm water, and got their data collected and graphed. I’m pretty sure that they found that the fish chemistry doubled every 10 degrees. Oh. That’s why fish in cold water are sluggish!

Once the lab was finished the fish were returned to the aquarium to live their best lives until they could be adop1ed out to new homes. Yep. These fish were a hot ticket item and there was a drawing to decide who could take one home.

Fish who didn’t get a home right away got to hang around for a second round of science. Did you know that if you carefully catch a goldfish, wrap it up in a wet paper towel, and then pop the tail under a microscope you can see the flow of blood through the tail? Yep!! It is pretty amazing! Here’s a YouTube video showing the blood moving though the blood vessels in the fish tail (really cool!), and here is another one showing a student doing the lab. The whole fish burrito treatment isn’t too hard on the fish if you get them back into the tank within ten minutes, and I only used one fish for each class as I could project the digital image from the microscope onto the classroom screen so everyone could see what was happening. You can count the pulse of the goldfish that way!

One day a student brought me come crayfish left over from his father’s restaurant order and we added them to the fish tank. Oops. Crayfish can catch goldfish. Talk about chaos in the classroom! Um… natural selection, anyone? Several fish were lost to the crayfish but one wiley little comet goldfish evaded the crayfish with ease and eventually outlived them all. It grew to become a 6 inch goldfish giant that the students named Fred. Fred learned to beg for food. Fred loved the 6th period class more than any other because they brought him scraps of lettuce and oranges from lunch every day. Fred was so big he had the whole tank to himself unless some little feeder fish were visiting for a lab. Fred went to another classroom one quarter during a big lab push in my classroom and we had to bring him back because students told me that Fred was getting scared and picked on in its new classroom habitat.

Yep. An important classroom lesson about the responsible and ethical care of the creatures under our control was delivered by… a goldfish.

When I left that school for another job in the district Fred came home with me and lived out the rest of his life in a bigger tank with some nice fancy goldfish to keep him company. I think that he still missed the students.

I’ve been thinking about goldfish lately because Mateo (AKA the CoalBear) needs lots of attention. There isn’t enough entertainment in the world to meet his needs. I have bought him lots of new toys. He chases feather teasers and the laser light every day. There are cat trees in the windows so he can watch the squirrels and the bunny. He gets tons of attention!

I’m now thinking of getting the cats a little goldfish tank to watch.

Yeah. A goldfish aquarium! That’s the ticket.

It’s not like I’m longing for a tank of fish. Oh, no, nothing like that.

Goldfish memories are the best.