Argentine Seabass
The Argentine sea bass — known locally as mero — is a reef-associated serranid that anchors the rocky-bottom fishery along Argentina's Atlantic coast.
Abundant on the Patagonian continental shelf, it's a staple target for coastal and boat anglers working rocky reefs from Buenos Aires province south through Patagonia.
Compact, sturdy, and reliably present around structure, it's one of the most consistently catchable marine species in Argentine waters.
Scientific Name: Acanthistius patachonicus
Also known as Mero, mero patagonico
- Brown to brassy body with broken dark vertical bars along the sides and scattered scribble-like markings across the flanks and fin bases — distinctive and easy to recognize in hand.
- Rounded tail fin and a gill cover that tapers to a point above the pectoral fin base; robust, thick-bodied build with a tall caudal peduncle.
- Spiny front section of the dorsal fin is prominent — the genus name literally means "thorn-sail" in Greek, and those spines are the first thing you notice.
- Typical size runs to about 31 cm; a solid fish for its class given the cold, productive shelf waters it inhabits.
What to know
Habitat Distribution
- Native to the southwestern Atlantic, found along Argentina's entire Atlantic coastline from the Buenos Aires province coast south through Patagonia to around 53°S.
- Lives on the continental shelf in colder waters, generally between 15 and 82 meters depth — a bottom-hugging species tied to hard substrate.
- One of the most conspicuous and abundant fish in rocky-reef assemblages along the Patagonian coast; described in research as a sedentary, site-attached species.
- Tolerates a sea temperature range of roughly 10–19°C, which matches the cold, nutrient-rich shelf waters off Argentine Patagonia.
Key Locations
- Patagonian Atlantic coast — the rocky reef systems from Chubut and Santa Cruz provinces south are the core of its Argentine range.
- Continental shelf waters off Buenos Aires province mark the northern edge of its consistent distribution in Argentina.
- Coastal rocky reefs accessible by boat from ports along the Patagonian coast, where hard-bottom habitat is abundant from nearshore to mid-shelf depths.
Specific Spots
- Rocky reef edges and hard-bottom structure are the core holding areas — this fish is sedentary and territorial, so once you find the rocks, you find the fish.
- Broken reef with relief — ledges, crevices, and boulder fields — concentrates fish more than flat hard bottom; depth transitions from 15 to 40 m are productive starting points from a boat.
- Current-swept reef points where baitfish stack up draw feeding fish to the edges of structure rather than deep inside it.
Argentine Seabass FAQ
Answers from onWater's species guide.
What are the best lures and bait for Argentine Seabass?
Vertical metal jigs worked near the bottom are the most reliable approach, match the weight to the depth and current so the jig stays in the strike zone on the reef.
When is the best time to fish for Argentine Seabass?
Available year-round in Argentine coastal waters, with no strongly defined seasonal absence documented in sources. Calmer sea conditions in late spring through early autumn (November–April) make boat access to offshore reef structure more practical along the Patagonian coast.
How do you catch Argentine Seabass?
Most anglers target mero from boats anchored or drifting over known rocky reef structure, dropping jigs or bait rigs to the bottom. Shore fishing from rocky coastal points is possible where reef extends close to land, but boat access to offshore structure produces more consistently.
What do Argentine Seabass eat?
Feeds primarily on smaller fish and invertebrates associated with reef habitat, crustaceans, small baitfish, and squid are the main forage. Jigs and soft-plastic shads that mimic small baitfish are the go-to conventional choices.
Where do Argentine Seabass live?
Native to the southwestern Atlantic, found along Argentina's entire Atlantic coastline from the Buenos Aires province coast south through Patagonia to around 53°S. Lives on the continental shelf in colder waters, generally between 15 and 82 meters depth, a bottom-hugging species tied to hard substrate.
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