Pygmy madtom
Noturus stanauli
The Pygmy madtom has a slender body, with a pale belly and dark, spotted dorsal surface, reaching lengths of up to 7.5 cm.
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About the Pygmy madtom
This is a tiny North American catfish from Tennessee's Clinch and Duck rivers that spends its days tucked under small rocks and comes out around dusk. Males guard small clutches of big eggs, which is fun to watch if you ever see footage from conservation hatcheries. It is federally endangered, so it is a fish for biologists with permits, not home aquariums.
Quick Facts
Size
4.2 cm (1.7 inches) TL
Temperament
Peaceful
Difficulty
Expert
Min Tank Size
20 gallons
Lifespan
1-2 years
Origin
North America (Tennessee River drainage, USA)
Diet
Carnivore - aquatic insect larvae and small invertebrates
Water Parameters
20-24°C
6.5-8
5-15 dGH
Need a heater for this species?
This species needs 20-24°C in a 20 gallon tank. Use our heater calculator to find the right wattage.
Calculate heater sizeCare Notes
- This species is federally endangered in the US, so double-check your permits and coordinate with your state biologist; do not buy or sell them without paperwork.
- Give them a cool, fast-flow tank in a long footprint tank (20+ gallons) with sand or fine gravel, flat rocks, and leaf litter; keep light low, cover every intake with sponge, and use a tight lid.
- Aim for 60-70 F (16-21 C), pH 6.8-7.5, 3-12 dGH, zero ammonia and nitrite, and nitrate under 10 ppm; strong aeration/flow is non-negotiable and small weekly water changes keep them stable.
- They feed after dark, so drop in live blackworms, chopped earthworms, frozen bloodworms, and small sinking carnivore pellets right after lights out; small portions 1-2x daily and pull leftovers.
- Skip tankmates; they are tiny, shy, and get outcompeted fast, and anything clawed or pushy (crayfish, cichlids, sunfish, larger catfish, loaches) will injure or eat them.
- If you try breeding, pack tight caves under flat rocks or 1 inch PVC; a cool winter at 55-60 F then a slow rise to 66-70 F can cue spawning, with the male guarding the clutch.
- Heat and low oxygen wipe them out quickly, so keep a fan or chiller and a backup air pump ready; avoid copper or formalin meds and treat in a separate tank if needed.
- Handle with a specimen cup, not a net, because they have sharp mildly venomous spines and delicate skin; block every gap and filter intake because they wedge themselves into tiny spaces.
Compatibility
Good Tankmates
- Small, calm cool-water schoolers like white clouds and redbelly dace that hang mid-top and leave the bottom alone
- Peaceful ricefish/medaka up top; same temp range, ignore the catfish, and make nice dithers
- Non-bossy shiners such as rainbow shiners as dithers, as long as you spread food around and toss extra after lights out so the madtoms actually eat
- Easygoing Etheostoma-type darters that perch on rocks but are not pushy; give lots of rock cracks and leaf litter so the madtoms can vanish when they want
- Peppered corys in a roomy footprint; mellow and cool-tolerant, but keep the group modest and target-feed the madtoms at night
- Quiet topwater killifish that are not nippy and do fine cool, like medaka or small Fundulus that ignore the bottom
Avoid
- Anything predatory or pushy like sunfish, cichlids, or larger catfish that will view a 1.5-2.5 inch madtom as a snack
- Bottom bullies and nonstop foragers such as yo-yo or skunk loaches and big plecos that will body-check them after dark
- Hyperactive food hogs like giant danios or big barbs that stress shy, nocturnal fish and vacuum up every pellet
- Big darters and sculpins that dominate the bottom and can inhale small catfish
Where they come from
Pygmy madtoms (Noturus stanauli) are tiny, bottom-hugging catfish from the upper Tennessee River system, mainly the Clinch and Powell rivers. Think cool, clear riffles with clean gravel and cobble, not mucky backwaters. They are one of the rarest North American fishes and are legally protected.
This species is federally protected in the U.S. Do not buy, sell, or collect them. My experience was under permits through a conservation program. If you see N. stanauli for sale, walk away - it is almost certainly illegal or misidentified.
Setting up their tank
If you are working with them under permits, think cool-water river tank. A 20-long or 30-breeder gives a good footprint. They appreciate steady current, tons of oxygen, and places to wedge themselves out of sight.
- Flow and oxygen: strong, laminar flow across the bottom. Aim for 10-20x turnover and highly aerated water.
- Temperature: 57-70 F (14-21 C). A chiller or a cool basement helps. They sulk in heat.
- Water: pH 6.8-7.6, soft to moderate hardness, very low nitrate. Absolutely no ammonia or nitrite.
- Substrate: fine gravel with rounded pebbles and small cobble. Keep it clean and silt-free.
- Hides: flat stones, narrow rock crevices, small PVC sections, or stacked slate with gaps just big enough for them.
I run a river-manifold style setup with powerheads pushing water through buried pipes to outlet sponges on one side. That gives a strong, single-direction flow and keeps detritus moving to the filter intakes.
Put sponge prefilters on every intake. These fish nose into everything and scrape easily. Dim the lighting and let leaf litter gather in back eddies for extra cover.
What to feed them
They are micro-predators with small mouths. Mine ignored flakes and big pellets for weeks. Start with live or wiggly foods, then sneak in prepared stuff once they are eating confidently.
- Live blackworms (well-rinsed) and whiteworms
- Frozen bloodworms and chopped mysis
- Small sinking carnivore pellets (soaked) mixed with bloodworms
- Occasional daphnia and scuds
Feed after lights out. A turkey baster is your friend for spot-feeding under stones. They learn where the food shows up and will poke their heads out once the room goes dark.
To wean onto prepared foods, thaw frozen bloodworms, mix in crushed pellets, and let it sit 10 minutes. Squirt small portions right into their hide. Over a couple weeks they start taking the pellets too.
How they behave and who they get along with
Shy, crepuscular, and very into tight spaces. They are not aggressive, but they will snap up tiny fry or shrimp that wander too close. In a group they often share the same flat rock, each with a corner to themselves.
Tankmates are tricky. Fast-water minnows and darters look right on paper, but most outcompete pygmies at feeding time. For conservation work, I keep them species-only. If you must mix, use just a few small, calm fish that accept food from the surface so your madtoms get the bottom offerings.
Skip crayfish and larger sunfish. Pinchers and big mouths turn these into expensive snacks.
Breeding tips
There is very little published on N. stanauli spawning. What worked for me mirrors other Noturus: seasonal cues, tight nest spaces, and peace and quiet. The male will claim a flat rock with a low ceiling and guard the nest.
- Season cycle: cool them to 50-54 F (10-12 C) for 6-8 weeks, then warm gradually to 64-68 F (18-20 C) with a longer photoperiod.
- Nests: offer lots of flat stones on spacers or small PVC caps laid sideways. Openings should be just big enough for one fish.
- Feeding up: heavy live/frozen foods for several weeks before warming.
- After eggs appear: keep flow steady but not blasting the nest. Minimize disturbance. The male usually fans and guards.
- Larvae: at 18-20 C, expect hatch about a week in. Start with microworms and newly hatched brine shrimp, then transition to chopped blackworms.
If you are part of an authorized program and get a spawn, document everything. Coordinate with your agency or institution on disposition of juveniles. This species is conservation-first.
Common problems to watch for
- Overheating and low oxygen: first signs are rapid gilling and hugging the highest-flow spot. Add air, drop temp, and increase surface agitation.
- Silted substrate: they hate gunk in their gills. Vacuum lightly and manage flow so fines get carried to the filter.
- Scrapes and fungus: sharp rock or bare intakes cause nicks that fuzz up. Round your stones, use sponge guards, and keep water pristine.
- Refusing food: they often need live movement to kickstart feeding. Try live blackworms at lights-out, then blend in frozen.
- Medication sensitivity: like many catfish, they react badly to copper and strong dyes. If you must treat, go gentle and isolate.
- Misidentification: many "pygmy madtoms" in photos are actually other Noturus. If you are not working from a permitted source, you likely do not have N. stanauli.
If you want a similar catfish for a home stream tank, look for legally collected, common Noturus like N. gyrinus (tadpole madtom) through reputable, permitted sources. They handle warmer rooms and are far easier to feed.
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