Black River madtom

Where they come from

Black River madtoms (Noturus maydeni) are a little slice of the Black River system in Missouri. Think cool, clean, fast-ish water running over rock and gravel, with lots of crevices and leaf packs. They are one of those native catfish that spend most of their life tucked under stuff, coming out to hunt when the lights are low.

Setting up their tank

Build the tank around hiding spots and current. If you set it up like a typical planted tropical tank with fine sand and slow flow, you will see them less and you will fight water quality more.

• Tank size: I would not bother with less than a 20 long for one, and 30-40 gallons is way nicer if you want a small group.
• Substrate: smooth gravel, small rounded cobble, or a sand-and-gravel mix. Skip sharp rock.
• Hardscape: flat stones stacked with gaps, rounded river rocks, and a couple chunks of driftwood. Make lots of "unders" and tight slots.
• Hides: small caves, rock piles, and even short sections of PVC work great if you tuck them out of sight.
• Flow and oxygen: a strong filter plus a powerhead or river-manifold style flow. They really respond well to moving water.
• Temperature: cool to mid-range. Aim roughly mid 60s to low 70s F if you can.
• Lighting: dim or broken up with floaters or hardscape shadows. Bright light just makes them clamp down and disappear.

Water quality has to be boringly stable. They are not fans of ammonia/nitrite at all, and they get stressed in dirty, low-oxygen water fast. I used to do smaller water changes more often rather than giant sporadic ones, just to keep things steady.

What to feed them

These are night-shift hunters. If you toss food in at noon and walk away, your other fish will eat it and the madtom will go hungry. Feed after lights out, or at least at dusk, and target the food to their hide entrances.

• Staples: sinking carnivore pellets (small catfish pellets), micro sticks, and quality sinking wafers with high protein.
• Best frozen foods: bloodworms, blackworms, mysis, chopped krill, brine shrimp (as a treat), and chopped earthworm.
• Live foods (great conditioning): blackworms, small nightcrawlers cut to size, scuds, and insect larvae if you culture them.
• Avoid: big messy feedings that rot under rocks. If you cannot see where it landed, you cannot tell if it got eaten.

They have small mouths compared to their "catfish" vibe, so size the food down. I do better with several small pieces than one big chunk that gets ignored and turns into an ammonia factory.

How they behave and who they get along with

Most of the time they are secretive and pretty chill. You will see them most at night: cruising the bottom, nosing around rock edges, then darting back under cover. They are not a "centerpiece" fish unless you enjoy flashlight viewing, which I do.

• With their own kind: can work in a roomy tank with lots of hides. Expect some shoving over favorite spots.
• Tankmates that usually work: cool-water minnows and shiners, dace, small suckers, darters that are not hyper-territorial, and other peaceful natives that like flow.
• Tankmates to avoid: aggressive/territorial bottom fish that claim caves, big predators that can swallow them, and fast piggy eaters that vacuum all sinking food before it lands.

One more thing people miss: madtoms have pectoral spines. They are not out to get you, but if you net them carelessly you can snag the net and stress the fish (and you). I move them with a small container whenever possible instead of a net.

Breeding tips

Breeding Noturus in home tanks is possible, but it is not the quick "drop in a pair" kind of project. If you are serious, think seasonal cues: cooler period, then a gradual warm-up with heavier feeding and lots of secure nesting cavities.

• Group vs pair: a small group gives you better odds than trying to sex a pair (sexing is not always obvious).
• Nests: tight caves, rock crevices, or small diameter PVC with one main entrance. They like a snug roof.
• Conditioning: lots of live/frozen foods, especially worms.
• Seasonal cue idea: a cool winter period (still well-oxygenated), then a slow temperature rise and big water changes to mimic spring.
• If you get eggs: keep flow and oxygen high. Males in many madtom species guard nests, so do not rush to pull the eggs unless you have a reason.

Common problems to watch for

Most issues I have seen come down to three things: warm water, low oxygen, and food rotting under hardscape. Fix those and they are surprisingly hardy for a small catfish.

• Not eating: usually feeding at the wrong time, too much bright light, or tankmates outcompeting them. Try feeding after dark and target feed.
• Hidden waste pockets: rock piles trap mulm. During maintenance, use a baster to blast crud out and siphon it.
• Oxygen stress: hanging in the open, gulping near surface, rapid breathing. Increase surface agitation and flow immediately.
• Fin damage/scrapes: sharp rocks and tight jagged crevices do it. Use smooth river stone and check your caves for rough edges.
• Ich and other parasites: stress-related, often after a temp swing or a new fish introduction. Quarantine new arrivals and keep temps stable.
• Handling injuries: spine snags from nets. Use a cup/container for moves.

If you are keeping them, you are already the kind of hobbyist who enjoys the weird, hidden fish. Give them current, clean water, and a bunch of rockwork, and they will settle in and start showing those little nighttime patrol behaviors that make madtoms so fun.