I helped to establish and care for the Zebrafish colony at Boston College. I routinely try to monitor for things like mold growth and parasites. Today, I used my Foldscope to check some fish tanks and I was surprised to see little worms moving around.. quite possibly parasitic nematodes! Some nematodes can live inside the digestive track of fish and cause problems with their growth and egg production, so it’s a good thing I had my handy Foldscope to check! If anyone is a worm expert, I’d love to know what type of worm this is.