There are certain animals you expect to find in a body of freshwater like the Tennessee River: Catfish, turtles, ducks, darters, maybe a snake or two.
What you don’t expect? Jellyfish.
Yet, as unlikely as it may seem, as Dr. Andreas Fath continues his point-to-point navigation of all 652 miles of the Tennessee River, he may encounter some unexpected wildlife, including — shockingly (though thankfully not sting-ingly) — freshwater jellyfish.
Freshwater Jellyfish are commonly found in many waterways in the eastern, temperate United States, including the Tennessee River. (Credit: Matt Hamilton/Tennessee Aquarium)
Small and bell-shaped, the Freshwater Jellyfish (Craspedacusta sowerbii) is translucent and measures 5-25 millimeters (0.2-1 inch). According to the U.S. Geological Survey, these jellies — also known as Peach Blossom Jellyfish — have been found in waterways throughout the U.S. and are most common in the eastern, temperate states. Actually, Dr. Fath may already have encountered these jellies during his 2014 Rheines Wasser study of the Rhine River, where they also have been sighted.
Freshwater Jellyfish do have stinging cells, but fortunately for Dr. Fath, they have not been proven to be able to pierce human skin.
While jellies may be one of the most unexpected animals Dr. Fath could encounter, they are not the ONLY strange creatures he may run into as his journey continues. Here are a few more oddities to be found in the Tennessee River drainage:
Bryzoans, also called “moss animals” are invertebrate that form colonies that appear as bubble-like masses. (Credit: Tennessee Aquarium)
- Bryzoans — Also called “Moss Animals,” these aquatic invertebrates are actually colonies of many individual animals, much like coral. Colonies of Bryzoans can grow in masses that may appear to be masses of bubbles. They may seem weird, but moss animals serve an important ecological function by cleaning the water as they filter feed.
A Chestnut Lamprey (Ichtyomyzon castaneus) attached to a Longnose Gar (Lepisoteus ossues) pulled from South Chickamauga Creek. Lamprey appear eel-like from above, but they use teeth on their “tongue” to rasp away scales and skin from host fish before feeding on their blood. (Credit: Bernie Kuhajda/Tennessee Aquarium)
- Lamprey (several species can be found in the Tennessee River) — Viewed from above, this order of jawless, scale-less fish looks like a long, slender eel, if one whose head ends in a flattened, disc-shaped mouth. From below, however, it looks like the stuff of nightmares thanks to a mouth packed with concentric rows of hooked teeth. Along with hagfish, lamprey are among the most ancient of fish species. Many lamprey attach themselves to a host, where their chompers get to work, either to feed on its flesh or on its blood. Fortunately for Dr. Fath, most freshwater lamprey species are fairly small, and humans aren’t among their typical prey.
A Paddlefish swimming through the Nickajack Lake exhibit at the Tennessee Aquarium. This species is named for its pronounced, elongated snout (or rostrum). (Credit: Casey Phillips/Tennessee Aquarium)
- Paddlefish — With its long, flattened snout (or rostrum) the origin of this species’ name aren’t hard to guess. Also known as the Spoonbill Cat and Shovelnose Cat, the Paddlefish is more closely related to a sturgeon than a catfish and is definitely one of the strangest-looking fish in the Tennessee River. An ancient species whose first appearance dates back 300 million years, long before the arrival of dinosaurs, the Paddlefish was once mistakenly identified as a shark. They feed by filtering the water, which they accomplish by opening their mouths staggeringly wide.
The Tennessee Bottlebrush Crayfish (Barbicambarus simmonsi), left, is twice as large as other crayfish species in its native habitat. It was discovered in a Tennessee creek in 2011 by scientists from the University of Illinois. (Credit: L. Brian Stauffer/UI News Bureau)
- Tennessee Bottlebrush Crayfish — The Tennessee River is home to dozens of species of crayfish, but the Tennessee Bottlebrush is definitely a stand out because of its sheer size. Crayfish, also known as Crawdads, Crawfish and Mudbugs, are freshwater crustaceans that look like the lobster’s smaller cousin. Well, most of them are smaller. The Tennessee Bottlebrush was discovered in a creek that drains into the Tennessee River in 2011. At five inches, it’s about twice the size of other crayfish in the region.