Gualeguay River

For the tararira a light-to-medium outfit is best, sturdy but comfortable to cast for hours. The setup depends on the method, but these are the specific recommendations:

Rod:

• For spinning with lures: a 1.80 to 2.10 m rod, fast action and medium power (medium / medium-heavy). Firm enough to set the hook in that bony mouth and to pull the fish out of the vegetation.
• For bottom fishing from the shore: a somewhat longer rod (2.40–3.00 m) that lets you cast the bait far.

Reel:

• Spinning reel size 2500 to 4000, with a good, smooth drag. Alternatively, a baitcasting reel for those who master it, widely used with lures.

Line:

• Braid of 15 to 30 lb: it's the best option because it has little stretch (firmer hooksets), doesn't get cut by the vegetation, and lets you pull the fish out of the structure with authority.
• If you prefer nylon (monofilament), use 0.35 to 0.45 mm.

Leader (essential):

• Flexible steel (steel wire) or thick fluorocarbon (0.60–0.80 mm) about 20–30 cm long. The tararira's teeth cut any thin line; without a leader you'll lose fish and lure for sure. Steel is the safest; thick fluorocarbon is a more discreet alternative in clear water.

Accessories:

• Long pliers for unhooking (don't put your fingers in that mouth), a glove, a boga-grip or landing net for handling, and strong, well-sharpened hooks (single or treble depending on the lure). Bring weedless lures to fish among the vegetation without snagging.

Light-to-medium gear, small hooks and plant-based bait (dough, corn) or worm. On the bottom or floating in the rapids; a favorite in shore competitions.

The gear must measure up to a strong fish that runs, jumps, and lives in current with structure. Specific recommendation:

Spinning (standard setup)

• Rod: spinning rod of 1.80 to 2.10 m, medium to medium-fast action and medium / medium-heavy power, with a good response for setting the hook in a hard mouth.
• Reel: a sturdy spinning reel size 3000 to 4000, with a progressive, reliable drag to hold up to the runs.
• Line: braided line of 20 to 30 lb; it gives sensitivity, low stretch for a solid hookset, and the load capacity for big fish.
• Leader: an anti-cut leader is essential because of the teeth: thin flexible steel (coated steel cable) or heavy fluorocarbon of 40-60 lb. Without it, the dorado cuts the line with a single bite.

For trophy specimens or big rivers: step up to a medium-heavy/heavy rod, a 4000-5000 reel, and 30-40 lb braid, with a steel leader.

Fly fishing

• Rod: #8 to #10, fast, to move large streamers and fight in current.
• Reel: with a good disc drag and backing capacity.
• Line: WF (weight forward) matched to the rod number; in fast water a sinking tip may be advisable.
• Tippet / leader: finish with an anti-cut section of steel or heavy fluorocarbon, just as in spinning.

Key accessories: strong, well-sharpened hooks (ideally barbless if you're going to release), long pliers to unhook without hurting yourself on the teeth, and if you practice catch and release, a knotless/rubber net and gloves to handle the fish carefully.