Native Fishes of Ohio

6. Catfish: Night Stalkers

53 Ictaluridae is one of the largest families of freshwater fish found in North America, with about fifty species among seven genera. Four genera represent the eastern United States: Ictalurus (channel, or fork-tailed, catfish), Ameiurus (bullheads), Pylodictis (flathead catfish), and Noturus (madtoms). All are easily identified by smooth, scaleless skin; four pairs of barbels, or whiskers, on the chin and upper jaw; and sharp spines on dorsal and pectoral fins. Any fisherman who has caught a catfish learns to respect these spines; particularly those sported by the madtoms. If carelessly handled, madtoms can deliver a venomous sting similar to that of a bee or wasp. Members of this family are also identified by their slightly flattened heads and the small, fleshy adipose fins on the dorsal surfaces of their bodies. Catfish are primarily active at night, moving onto riffles and shoals to feed. Photoreceptors in the fish’s eyes gather ambient light, which shines onto the fishes’ retinas, enabling them to see in almost total darkness. With receptors on their barbels and lips, they have a highly developed sense of smell, evidenced by the variety of stinkbaits anglers use to attract them. While they can be captured during daylight hours, the serious angler waits until dark. For a biologist standing in a riffle at night with a seine full of fish, glowing eyes reflected in the headlamp mean catfish. At thirty species, madtoms are the most diverse and interesting members of the family. They are small fish adapted to a variety of stream habitats whose cryptic coloring camouflages them from predators. Differentiating among the different species can be difficult, but identifying characteristics include differences in pigmentation patterns and shape and size of pectoral Catfish Night Stalkers C h a p t e r 6 54 Native Fishes of Ohio and dorsal fins. Many have limited ranges and, like the darters and shiners, exhibit a high degree of endemism, particularly in the southern United States. Limited ranges and an intolerance of pollution and habitat degradation have resulted in no fewer than five species being listed as federally endangered. Ohio has one of these, the Scioto madtom, known only in a single riffle complex in lower Big Darby Creek. Only twenty-three individuals have ever been captured, the last specimens collected in 1957. In addition to the Scioto, five other species of madtoms are known in the state. Northern madtoms are currently listed as state endangered, and the mountain madtom is listed as threatened. Increasing populations of mountain madtoms were identified in the Muskingum and Little Miami Rivers in the 1980s and 1990s. More recently, this species has been expanding its range in both systems and has also been reported from other drainages. Northern madtoms are found in small numbers in the main stem of the Muskingum River and in other widely scattered locales, like Big Darby Creek in central Ohio and the Whitewater River in southwestern Ohio. Madtoms hide under rocks or bury themselves in loose gravel, only coming out at night to forage. Stonecats are Ohio’s largest madtom, sometimes twelve inches long. Their common name comes from their habit of hiding under flat rocks in large streams. Stonecats also inhabit rocky shorelines and reefs in Lake Erie, where wave actions and currents mimic stream conditions. Ranging statewide, brindled madtoms are inhabitants of low-gradient riffles and pools, where they are commonly found hiding in woody debris, leaves, and undercut banks. Like mountain and northern madtoms, brindleds are more easily captured in the fall. Tadpole madtoms favor quiet pools with rooted aquatic vegetation and organic debris; they also inhabit weedy glacial lakes, river oxbows, and other wetlands. Their populations are now greatly reduced by habitat destruction. When spawning, female madtoms attach sticky eggs to the underside of rocks and woody debris. They also use man-made objects, like broken crockery. Crayfish burrows and discarded beverage cans also make suitable homes for brindled and tadpole madtoms. Northern, mountain, and stonecat madtoms prefer flat rocks in riffles. Males of all species guard their eggs and young until they disperse from the nest site. Diets include a variety of aquatic insect larvae and microcrustaceans. Adult stonecats also prey on small fish, worms, and hellgrammites. Unlike madtoms, which favor rocky riffles and runs, bullheads in the genus Ameiurus are inhabitants of river pools and lakes. Ohio is home to three of the seven species in this genus: yellow, black, and brown bullheads. [18.117.9.186] Project MUSE (2024-04-26 05:07...