Freshwater · Year-round encounter; warm nights May to September are best
Tadpole Madtom
Noturus gyrinus
The tadpole madtom is a tiny catfish rounded like a tadpole, familiar from the aquarium trade and mostly met as an identification encounter while micro-fishing. Handle it with real care: the serrated spines in its dorsal and pectoral fins carry a mild venom that stings like a bee. It hides by day and feeds at night.
Seasons · Peak
Identifying features
- Rounded, tadpole-like body with a blunt, broad head
- Adipose fin joined smoothly to the rounded tail fin with no deep notch
- Yellowish-brown back and sides with a pale belly
- Short whiskers (barbels) around a small mouth
- Serrated dorsal and pectoral spines linked to venom glands — handle with care
Habits
- Nocturnal — hides under rocks, logs and debris by day
- Pectoral and dorsal spine stings feel like a bee sting; use wet hands and avoid the spines
- Feeds at night on insect larvae, small crustaceans and snails
- Spawns in summer; eggs are laid under stones or debris and guarded by the male
- A popular aquarium-trade micro catfish, collected and admired more than fished
Distribution
Where to find them
- Weedy margins of lakes in the Iowa-Missouri and Great Lakes country
- Slow, debris-filled stream pools in Minnesota and Tennessee-Kentucky
- Deep South backwaters and soft-bottom lake bays at night
Where they live
How to catch them
Micro baits on weedy lake edges Lake
Rig: Ultralight rod, size 16-20 hook with a tiny worm piece under a small float or on a light bottom rig near weeds
Bait/lure: Tiny worm pieces
Key tip: Treat it as an identification encounter — photograph it in hand carefully, avoiding the spines, and release it.
Night fishing with the smallest hooks River
Rig: Smallest hooks (size 18-20) with worm scraps, fished after dark along slow stream pools and debris edges
Bait/lure: Worm scraps, bloodworms
Key tip: Fish after dark when madtoms leave cover, and use a small net rather than grabbing the fish.
Best baits & lures
Baseline setup
- Rod: Ultralight 5-6 ft spinning rod
- Line: 2-4 lb mono
- Terminal: Size 16-20 hooks, tiny floats, split shot
Recommended gear for this species
Rod · Best value
9' 5-weight fly rod outfit
≈ US$180-260
Covers chironomid lakes and small rivers with one setup.
Flies · Budget
Chironomid assortment (30 patterns)
≈ US$25-40
Chironomids are 60% of a lake rainbow's diet in spring.
Picks come from our rule library — never paid placements. Prices are guides; affiliate links may earn us a commission.
Typical size
Common 2-3 in (5-8 cm); large fish to about 5 in (13 cm)
On the table
Not a food fish — far too small, and its spines are venomous; release it carefully.
Similar species
StonecatThe stonecat is larger and more slender, living in rocky flowing streams, with the adipose fin more separate; the tadpole madtom is smaller, rounder and tadpole-shaped in still weedy water
Yellow BullheadThe yellow bullhead grows far larger, to a foot or more, with longer whiskers and a bigger mouth; the tadpole madtom stays under about 5 in with a rounded tadpole bodyRegulations vary by area and can change in-season — always check the official rules for your area before you fish. Regulations guide →
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