School Shark
The school shark (cazón) is the centerpiece of Argentina's most important directed shark fishery, with a long-running gill-net fleet operating out of Necochea.
It also draws growing catch-and-release interest from sport anglers, particularly around Península Valdés and Bahía Anegada. Critically endangered in the South West Atlantic, it's a species where every release genuinely matters.
Scientific Name: Galeorhinus galeus
Also known as cazón, tope, soupfin shark
- Slender, elongated body with a distinctly large second dorsal fin nearly equal in size to the first — a key ID feature separating it from most other coastal sharks.
- Grayish-brown or slate above, fading to white or pale cream on the belly; no prominent markings or spots.
- Long, pointed snout and large eyes give it a lean, almost greyhound-like profile compared to stockier coastal sharks.
- Typical adults run 1–1.5 m; the species can reach close to 2 m, though fish that size are increasingly rare in Argentine waters.
What to know
Habitat Distribution
- Native to the South West Atlantic; found along Argentina's entire continental shelf from the Río de la Plata estuary south through Patagonia, including the North Patagonian Gulfs.
- Moves through gulf, shelf, and shelf-slope waters — from shallow coastal bays to depths around 600–800 m, though most encounters happen in nearshore and mid-shelf zones.
- Shows a strong seasonal presence in Golfo Nuevo (Península Valdés), with peak abundance from mid-summer through autumn and lowest numbers in spring.
- Tagged individuals have demonstrated large-scale latitudinal migrations — one female moved roughly 1,425 km from Golfo Nuevo to Uruguayan shelf waters in a single season, confirming a transnational population.
Key Locations
- Golfo Nuevo (Península Valdés, Chubut) — the best-studied sport-fishing area; peak abundance mid-summer to autumn, with ongoing tagging research.
- Bahía Anegada (Buenos Aires province) — detailed diet studies confirm seasonal concentrations of both juveniles and adults from October through April.
- Necochea (Buenos Aires province) — home to the most important directed school shark fishery in the South West Atlantic, historically centered on gill-net boats working the nearshore shelf.
- Rocas Coloradas and southern Chubut coast — school sharks are regularly encountered by artisanal fishers working this stretch of Patagonian coastline.
Specific Spots
- In Bahía Anegada, adults concentrate over soft-bottom areas where Atlantic midshipman and squid are seasonally abundant — follow the bait, not just the structure.
- In Golfo Nuevo, sharks use the deeper channel edges and drop-offs during their seasonal residency; mid-water and near-bottom presentations both produce.
- Around Necochea and the Buenos Aires coast, gill-net fishers work the nearshore shelf; sport anglers target the same zone from boats, drifting cut bait over sandy bottom.
School Shark FAQ
Answers from onWater's species guide.
What are the best lures and bait for School Shark?
Whole squid or large squid-strip baits are the top choice, especially in autumn when adults are actively selecting squid over other prey. Cut fish, mackerel, bonito, or any oily local baitfish, fished on the bottom works well from December through February when the diet shifts toward benthic fish.
When is the best time to fish for School Shark?
Summer (December–February): peak inshore abundance in Golfo Nuevo and Bahía Anegada; adults feeding heavily on benthic fish. Autumn (March–April): squid becomes the dominant prey; fish remain accessible in gulf and shelf waters before beginning their northward migration.
How do you catch School Shark?
Most sport anglers in Argentina target school sharks from small to mid-size boats, drifting or anchoring over sandy or mixed bottom and fishing cut squid or fish bait near the seabed.
What do School Shark eat?
Adults eat mainly bony fish and squid, in Bahía Anegada, benthic fish like the Atlantic midshipman dominate the diet from December through February, then squid takes over in March–April. Cut fish or squid fished near bottom covers both windows.
Where do School Shark live?
Native to the South West Atlantic; found along Argentina's entire continental shelf from the Río de la Plata estuary south through Patagonia, including the North Patagonian Gulfs.
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