How do you know if the brackish or salt water you are swimming in is unpolluted? Look for a Diamondback Terrapin: they are water snobs. Since they do consume quite a bit of salt between the water that they swim in and the food that they eat (fish, marine snails, crabs, marine and tidal mollusks, carrion, clams, and worms), the excess salt is excreted through special glands at the eye. Imagine their eye-boogers for a moment, if you please. The Diamondback Terrapin is the state reptile of Maryland (I didn’t even know that states had state reptiles) and also the official mascot of the University of Maryland College Park. They get their name from the diamond-shaped concentric growth rings on their shell. You can determine their age by counting the rings or by asking them directly.
Because of human dumminess, the Diamondback Terrapin is listed as “near threatened” on the IUCN’s endangered list. Their populations were decimated from the late 1880s to the early 1900s due to commercial harvest for turtle soup. The demand for terrapins ended by the 1930s as a result of people eating all the turtles and because of Prohibition, as sherry was another of the soup’s key ingredients. Turtle soup? Gross and mean, People! Luckily, there are many research groups and organizations that are fighting to save these slow-walking creatures from extinction.