Noturus flavus

Description

Stonecats are small, slender, flat-headed catfishes, with the adipose fin keellike and continuous with the dorsal fin except for a shallow notch. The upper jaw projects beyond the lower jaw and the tooth pad on the upper jaw has a narrow, crescent-shaped extension on each side. There are lateral backward extensions on the premaxillary band of teeth. Whereas the dorsal and pectoral spines of most members of this family cause wounds that irritate, the stonecat has poison glands, particularly on the bases of the pectoral spines, that cause extreme pain similar to that of a wasp sting with just one prick. The pectoral fin lacks any posterior serrae. Anal fin rays number 15 to 18, pectoral fin rays 9 to 11, and pelvic fin rays 8 to 10. The caudal fin rays number 55 to 67. The skin of the stonecat is thick and is yellowish brown in color, the sides of the head shade to yellow, and the belly is whitish. The stonecat has two forms. In the Cumberland drainage in Tennessee, a scientifically undescribed form of the stonecat possesses two light bars (perpendicular to body length) on its nape. In other areas, there exists a patch in place of the bars. In both forms, the stonecat has a white spot at the rear of the dorsal fin base and one 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/Age

Stonecats typically reach 4 to 8 inches, but can reach 12 inches. The stonecat reaches weights of 0.22 lbs up to 1.1 lbs. They also typically 5 to 6 years.

Distribution

The stonecat has a widespread distribution. It exists in the Great Lakes, the St. Lawrence River, drainages of Hudson Bay, and the Mississippi River basin. It can be found from the Hudson River drainage of New York west to the Red River drainage of Hudson Bay. It is found in drainages of the Mississippi River basin from Quebec to Alberta, southerly to northern Alabama and Mississippi, and westerly to northeastern Oklahoma.

Habitat

Stonecats live in freshwater environments. They are found in large creeks and small rivers. They occasionally occur in tiny creeks or rivers as large as the lower Mississippi. Stonecats occupy gently to fast moving riffle areas that have a rocky substrate. Stonecats spend the majority of their time in moderate moving, shallow riffles. They can also be found in deeper water in the 2 to 3 meter range. Stonecats also occur in natural lakes such as Lake Erie. There they prefer rock and gravel bars that are subject to a lot of wave action.

Diet

The stonecat is a benthic, opportunistic feeder, using its sensitive barbels during the night to search for food on the river bottom. They eat a diversity of food items such as immature aquatic insects such as mayflies, mollusks, minnows, fish eggs, isopods, amphipods, crayfish, plant material, other fish eggs, worms, and chilopods.

Reproduction

Females mature at three to fours years of age and a mean standard length of 4.7 inches. Stonecats form monogamous pairs for breeding and spawn when water temperatures reach 25 degree C. 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. The eggs are amber-yellow and are very large, ranging between 3.5 and 4mm diameter, with the whole egg mass enveloped by a gelatinous material. A female stonecat may produce between 200 and 1,200 eggs per year. They exhibit parental care, with the male or both sexes guarding the clutch. They continue to guard them even when they're still young until they head to shallower calmer streams and waters to mature.

Etymology

Noturus means "Back Tail" referring to the fusion of the adipose and caudal fins

flavus means yellow referring to the color distinction

Importance to Humans/Conservation status

Stonecats serve as indicators of water quality. They are not present in highly polluted areas or areas with a large amount of siltation. Stonecats are a very valuable indicator species to humans.

The US Endangered Species Act list the status of Noturus flavus as not threatened or no special status, meaning that there is no threat of this species going extinct.