The All-American Riffle Kitty

The Stonecat Madtom, or Stonecat (Noturus flavus), was described in 1818 by famed French biologist Constantine Samuel Rafinesque. The name Noturus means "back tail," coming from their connected adipose and caudal (tail) fins. flavus means "yellow," describing the many shades of yellow these fish display. If you think this fish looks familiar, it is probably, because we covered their close cousin, the Brindled Madtom, a few articles ago. Like with the Brindled Madtom, Channel or Flathead Catfish are the "large and in charge" relatives of the Family. The key characters that separate Stonecats from their cousins are: an overhanging top jaw and a light spot behind their dorsal fin. Stonecats can reach a maximum length of 31 cm (roughly 12 in).

A prime example of a Stonecat from a tributary stream of the West Branch DuPage River, IL. Notice the light patch behind the dorsal fin and its large mouth.

Stonecats primarily reside in rivers and streams but can be found in natural lakes with good flow. The preferred habitat is rocky riffles with continuous flow moving over them. These rocky areas will provide food, shelter, and mating grounds. During the daytime, one can find multiple individuals hiding under a large rock, waiting for the sun to go down.

Stonecats are opportunistic feeders, which means that they will eat almost anything that comes near them. This kind of diet includes aquatic insects, crayfish, plants, and even other fish; as long as it can fit inside their mouth, they will attempt to eat it. They use their barbels, or "whiskers," like taste buds to sense out potential prey. Once they have found something to their liking, they will squeeze into crevices or snatch it out of the water column.

A large, colorful Stonecat from a tributary of the Tuscarawas River, northeast OH.

Like their cousins, the Stonecat is nocturnal and most active during low-light hours when the likelihood of being eaten decreases. Predation on the Madtom genus can prove difficult because they pack a powerful venom in their dorsal and pectoral spines. For humans, grabbing hold of a Stonecat can potentially lead to an intense burning sensation that reaches up to the shoulder and lasts minutes. Though, this trait does not allow them to be uneaten. They can fall prey to turtles, snakes, Smallmouth Bass, and Longnose Gar!

Facial view of a Stonecat from the West Branch DuPage River, IL

Stonecats begin their spawning season when the water starts to reach 25C (77F). Unlike most fish, Stonecats are monogamous when it comes to mating pairs. These pairs select large, flat rocks mainly within a riffle or run but will also use pools. Females will lay 200 to 1,200 eggs within a gelatinous mass on the underside of their nesting rock. Care for the eggs is provided by either the male alone or both sexes. Parents will guard the nest until their young can leave and start the journey once more.

Stonecats have an expansive range, extending from Vermont out west to central Montana and down into Louisiana. The image above from Fish Map shows watersheds that Stonecats currently occupy (gray) and their historic occurrences (red). Presently, they are not threatened or endangered in any part of their range. However, this species is intolerant of pollutants and highly sensitive to siltation and altered stream conditions. Because of this, Stonecats are considered a valuable indicator species of stream or river health.

There are two great ways to observe Stonecats. One is to grab a flashlight and go wade a stream in the dark, looking for them to swim out from under their rock. The second is to get a net and perform a riffle kick; this is where you find rocky habitat with good flow, put the net downstream, and drag your feet towards the net, which moves the fish out of their hiding spots. When handling Stonecats, just remember to be extremely cautious because if you don't, they won't let you forget them! No matter how you choose to observe them, make sure you continually enjoy, protect, and enhance our freshwater habitats!