Northern Madtom

Noturus stigmosus is a moderately rare madtom catfish restricted to large rivers and their tributaries in the Great Lakes and St. Lawrence drainage in the United States and Canada. It is one of the larger madtoms at up to 9 cm, with a bold pattern of dark blotches and saddles on a pale background and a characteristic dark blotch at the anterior dorsal fin base. Its restricted range and association with clean, large-river habitats make it an uncommon species in the hobby.

In the aquarium, Northern Madtoms are best kept in cool, very clean water with moderate to strong current and a substrate of clean gravel and large flat stones providing shelter. Their sensitivity to poor water quality reflects their natural association with unimpacted large-river habitats. They are nocturnal and rarely visible during daylight hours.

Given their rarity in the hobby and conservation sensitivity of some populations, captive-raised stock should always be sought. They are rewarding for the dedicated native fish specialist who can provide appropriately cool, clean, large-river conditions.

Water: 12–22 °C, pH 6.5–8.0, moderate to hard; very clean, high oxygen, strong current. Tank: 80 L minimum; large flat stones, clean gravel; excellent biological filtration essential. Feeding: Live/frozen invertebrates, worms; sinking pellets and carnivore tablets at dusk. Breeding: Cavity nester under flat stones; male guards; pair bond needed for spawning success. Compatibility: Semi-aggressive; compatible with darters and similarly sized cool-water natives.