Captive Care Notes: Stonerollers (Campostoma, Family Cyprinidae)
Stonerollers come from cool waters, so it's important to keep them cool in the collecting bucket and transport container. Adult specimens can be temperamental when placed into an existing community tank, and can be harder to acclimate; juvenile specimens are more peaceful and acclimate to aquarium conditions more readily. Just make sure the water is cool and well oxygenated. Captive stonerollers eat all aquarium foods with gusto, but it's essential that they receive some vegetable matter in their diet. If the aquarium doesn't have a growth of algae, which stonerollers will happily keep in check, provide a Spirulina-based flake food. Stonerollers are heavy eaters and appear to need a lot of food. I keep a small group of Largescale Stoneroller (Campostoma oligolepis) fat and growing with liberal feedings of live blackworms and all the algae they can eat. When plastic plants from other aquaria get covered with algae, I place them in the stoneroller tank for a few days and they fastidiously pick it clean.
So far the only reported way to get stoneroller to spawn in the aquarium is to collect them just before they get into the act. Writing in the NANFA publication American Currents in 1993, Jon Wojtowicz reported collecting 15 cm (6 in) tuberculate male Central Stoneroller (C. anomalum) from Ohio's Big Darby Creek in January. He placed two pairs in a 15-gallon "long" aquarium in an unheated garage. Water temperature was 6C (45F). A three-inch layer of 3/8" gravel covered an undergravel filter. One morning Wojtowicz noticed that a pit, measuring 3" x 9" and deep enough to expose the filter plate, had been dug on one side of the aquarium. The next morning the pit had been moved, and one of the males was busy digging and defending it. Wojtowicz watched for an hour and his patience paid off. The two females approached the pit and individually spawned with the male several times. Unfortunately, Wojtowicz had to leave for work and was unable to separate the fish. By the time he got home, the other fish in the tank -- Longnose Dace (Rhinichthys cataractae) and a small Stonecat (Noturus flavus) -- had eaten the eggs. The fish never spawned again, although the male kept filling in and redigging his pit for about a week. All spawning activity came to an abrupt halt when a severe cold snap froze the water and killed the fish.
A similar account, also from American Currents, was reported by NANFA member Travis Haas in 2001. Three male and three female Central Stoneroller were collected from a Wisconsin stream in early spring and placed into a 40-gallon "long" aquarium, also kept in an unheated garage. A few days later pairs were seen swimming rapidly and pushing against each other. Nest building and egg deposition were not observed. Parents died from poor tank conditions or jumped out of the tank before the eggs hatched. Fry fed on powdered daphnia and algae that was growing in the tank.