Freshwater Cobbler
The freshwater cobbler is the largest native freshwater fish in south-west Western Australia — a mottled brown catfish found nowhere else on earth.
Anglers target it in the rivers and reservoirs between the Moore and Frankland rivers, mostly after dark with bait on the bottom. It's a genuine table fish with a reputation for delivering a nasty sting if handled carelessly.
Scientific Name: Tandanus bostocki
Also known as Cobbler, freshwater catfish
- Dark brown body with mottled or spotted patterning that becomes more visible in clear water; belly is lighter; scaleless, smooth skin.
- Distinctive eel-like rear end — the second dorsal, caudal and anal fins are fused into one continuous fin running from mid-back to the tail tip.
- Four pairs of barbels (whiskers) surround the mouth — the feature that earns it the 'catfish' name.
- Typically 30–40 cm; larger fish reach 50 cm. A handful of reservoir fish have exceeded 80 cm, though that's genuinely rare.
What to know
Habitat Distribution
- Endemic to south-western WA — found only in coastal drainages from the Moore River (near Gingin) south to the Frankland River near Denmark.
- Slow-moving streams, isolated river pools, reservoirs and some freshwater lakes; tolerant of brackish conditions near tidal influence.
- Swims close to rocky, gravelly or sandy bottoms; shelters in undercut banks and among the submerged root mounds of sedge tussocks.
- Also recorded in large water supply dams across the south-west, where some of the biggest individuals have been found.
Key Locations
- Swan River (Perth) — cobbler are present, though numbers are lower than historical levels; night fishing near Heirisson Island has produced fish.
- Harvey and Brunswick rivers (south-west WA) — subject to acoustic tracking research; known cobbler habitat with slow pools and suitable bottom structure.
- Frankland River (south coast) — southern edge of the species' range; slow reaches hold fish.
- Large water supply reservoirs across the south-west — some of the biggest cobbler on record have come from these impoundments, though access is restricted at Water Corporation dams.
Specific Spots
- Undercut banks and submerged root mounds of sedge tussocks — cobbler use these as daytime refuges and return to them after feeding at night.
- Isolated deep pools in river beds during low-flow periods, where fish concentrate as surrounding water recedes.
- Rocky or gravelly bottom sections of slow reaches — cobbler forage along the substrate and rarely move far from hard structure.
- Reservoir margins near submerged timber or rock rubble, especially where depth drops away from a shallow flat.
Freshwater Cobbler FAQ
Answers from onWater's species guide.
What are the best lures and bait for Freshwater Cobbler?
Earthworms and garden worms are the most reliable bait, easy to source, stay on the hook, and match the invertebrates cobbler root out along the bottom at night. Freshwater yabby tails and whole small yabbies work well, particularly in rivers where yabbies are a natural part of the cobbler's diet.
When is the best time to fish for Freshwater Cobbler?
Spring and summer (September–February), warmer water temperatures increase nocturnal feeding activity; generally the most productive period. Autumn (March–May), fish remain active as temperatures ease; good fishing continues into the cooler months in slower, deeper pools.
How do you catch Freshwater Cobbler?
Most cobbler fishing in WA is done from the bank after dark, with bait fished on a running sinker rig hard on the bottom in slow pools or reservoir margins. Boat fishing is also practical on larger impoundments. The key is patience, find the right bottom structure, put the bait down, and wait.
What do Freshwater Cobbler eat?
Bottom-dwelling invertebrates, worms, freshwater yabbies, shrimp and insect larvae, make up the bulk of the diet. Worms and yabbies on a running sinker rig fished hard on the bottom are the go-to bait choices.
Where do Freshwater Cobbler live?
Endemic to south-western WA, found only in coastal drainages from the Moore River (near Gingin) south to the Frankland River near Denmark. Slow-moving streams, isolated river pools, reservoirs and some freshwater lakes; tolerant of brackish conditions near tidal influence.
See it in the app
Most maps show you water.
onWater shows you Freshwater Cobbler.
- 01 · Species map filter
Map every Freshwater Cobbler water
Pick Freshwater Cobbler and the map zeroes in on the waters they call home. No more guessing which lake holds them.
- 02 · Waterbody species
Tap any water. See what lives there.
Species, behavior and seasonal patterns for every lake, river and pond, before you leave the driveway.
- 03 · Angler Intelligence
Ask how to catch Freshwater Cobbler
Tactics, gear and timing from onWater's AI fishing guide, tuned to the species and the water you're on.
Stop guessing where Freshwater Cobbler are.
Open the map, filter by Freshwater Cobbler, and head to water that holds them. Download onWater and plan your next trip in minutes.
- Species map filter
- Angler Intelligence
- Fishing journal
Explore other species
Trout, bass, salmon, panfish and everything in between. Each guide unpacks the behavior, seasons, and tactics that put fish in the net.
No species information available.
Smarter Fishing Starts in the App.
onWater Fish gives you everything you need to plan smarter, fish better, and own every trip from first cast to last.