Isopods galore!

]Giant Isopod

via Wikimedia Commons

During our walk for our last Book Talk and Walk I mentioned the pill bugs we saw under some logs. These interesting critters are not bugs or insects at all. But rather belong to another group of arthropods the crustaceans. The crustaceans are a diverse group that include familiar animals such as crabs, shrimp, lobsters, and crayfish. The familiar pill bugs that you find in your yard or garden and local woods under logs, leaf litter, outdoor plant pots and any other moist spot belong to a group of crustaceans that are called isopods. There are about 10,000 species of isopods worldwide. They are found in the deep sea, shallow oceans, freshwater, forest and garden and even in desert. They also vary in size with some species very tiny and some like the deep sea giant isopod (pictured) getting quite large. The giant isopod gets as large as a foot and lives at depths of 4000 feet. Most isopod species are scavengers feeding on detritus and dead organisms. A few species are predatory and actively hunt for food. Many isopod species are parasites especially on fish. They latch on to gills or another part of the fish and feed on the blood. In one bizarre case an isopod parasite will eat the tongue of the fish and live in the mouth of the fish replacing the original tongue!

So next time you see pill bugs in your garden soil all rolled up or scattering this way and that remember that you are observing terrestrial crustaceans that are part of a diverse group of interesting animals found all over the world in many kinds of habitats. I hope you appreciate the humble isopod and its place in the wonderful diversity of life on our living planet.

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