The stonecat is a widely distributed and relatively common member of the madtoms. It is the largest madtom in body size, is the species with the longest life span, and has a lower relative fecundity than other madtoms. It may be used for bait, especially in bass ﬁshing.
IdentificationStonecats are olive, yellowish, or slate colored on the upper half of their bodies and are the only madtoms that exceed 7 inches in total length. The stonecat has backward extensions from the sides of the toothpatch on the roof of its mouth. In most cases, the stonecat has a patch on its nape, a white spot at the rear of the dorsal ﬁn base, and another white spot on the upper edge of the caudal ﬁn. There are either no or a few weak teeth on the rear of the pectoral spine.
Size/AgeOf 261 specimens collected from Missouri and Illinois streams, the largest specimens were a 7-inch male and a 6.4-inch female. Growth is fastest in the ﬁrst year of life. Individuals up to 5.3 inches are at least 3 years of age. Individuals greater than 6.5 inches are 4 years and older. The largest and oldest stonecat ever collected was 12.25 inches in total length and 9 years old.
Spawning behaviorFemales mature at 3 to 4 years of age and a mean standard length of 4.7 inches. Clutches are guarded by males under large ﬂat rocks in pools or crests of rifﬂes. Rocks used as spawning cover averaged 200 square inches and were found in water averaging 34 inches deep.
FoodMayfly larvae are important food for all sizes of stonecat. Excluding those specimens greater than 4.7 inches in standard length, all stonecats consume stoneﬂy, caddisﬂy, and midge larvae.
Stonecats less than 3.1 inches in standard length consume blackﬂy larvae, whereas larger stonecats consume more crayﬁsh. Like most typical madtoms, stonecats consume a variety of organisms that are only infrequent prey, including ﬁsh eggs, worms, amphipods, and chilopods.