Central Stoneroller

Campostoma anomalum is a uniquely specialised minnow widely distributed across central and eastern North American streams. Unlike most cyprinids, it is a dedicated herbivore, using its hard cartilaginous lower jaw to scrape periphyton, algae, and detritus from rock and substrate surfaces — a feeding behaviour that makes it a living biotope maintenance tool. Males in breeding condition are genuinely striking: the snout and top of the head become covered in hard nuptial tubercles, and the pectoral, pelvic, and anal fins develop vivid orange-red pigmentation.

In the aquarium, Central Stonerollers are hardy, active, and adaptable to a range of cool-water conditions. They thrive in tanks with smooth rocks and flat substrate surfaces colonised by algae, which they will continuously graze throughout the day. Supplementing with blanched vegetables, spirulina wafers, and algae-based foods ensures complete nutrition.

They are peaceful toward other species and prefer to be kept in small groups that reflect their natural aggregating behaviour. Their constant activity and interesting feeding posture — angled head-down against surfaces — make them entertaining and functional aquarium inhabitants.

Water: 12–24 °C, pH 6.5–8.0, moderate hardness; good flow and oxygenation. Tank: 200 L minimum; smooth flat rocks with algae growth, coarse gravel, open swimming areas. Feeding: Algae, periphyton, spirulina wafers, blanched courgette and spinach; accepts sinking algae pellets readily. Breeding: Males build pebble pit nests; tubercle development signals breeding readiness — spawning easy to trigger. Compatibility: Peaceful; keep in groups of 4+; excellent community fish with other cool-water natives.