The latex glove was a streaky, dirty, yellow-gray, the color of a plastic bag that somersaulted into a tree and got tangled in the branches. When citizen scientists in the Netherlands spotted it in August 2020 while collecting trash along Leiden’s Oude Vest canal, they noticed something unsettling. The glove was torn, and wedged inside a gash beneath the thumb, they saw a tail. It was fringed and a bit rufous, and belonged to a creature that swam in and never found its way out. That unfortunate fish—a European perch,…
