snoek
Thyrsites atun · Gempylidae · predator
The long, blue, toothy fish of the cold waters of Chile and Argentina, which comes close to shore after anchoveta and sardine. It strikes corrico and jigs and is the famous Chilean "sierra ahumada".
Also called: sierra-chilena, sierra, senuca
- common size
- 60–90 cm
- maximum
- 200 cm
- common weight
- 1.5–3 kg
- record/max.
- 6.0 kg
- depth
- 0–150 m
- ideal water
- 13–18 °C
the right time
to be on the water
Choose the place and the species. The index, from 0 to 100, combines weather, sun, moon and tide with each fish's habits. Up to 28 days, with each day's confidence.
Reading the weather across 3 global models and 31 simulations…
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hour by hour
tap or drag on the chart to read each hour · on a keyboard, arrow keyssee hour-by-hour table
why this index at —?
choose the day
Each card shows the day's index (0 to 100) and, below it, a strip with the index for each hour, from 0h to 23h. from poor to excellent.
the fishing month at a glance
what's the best window for the crew?
Choose how many fishing days. We compare each stretch by its average index, discount days with a warning or closed season, and show the 3 best.
trend for the coming weeks
Line: the middle value of 31 simulations of the American GEFS model. Band: where 8 out of 10 fall. Narrow, firm trend; wide, high uncertainty.
everything about the snoek
who is the snoek
The snoek (sierra-chilena) is a gempylid, a family of elongated fish with strong teeth related to the escolars, from the temperate waters of the Southern Hemisphere: Chile, southern Peru, Argentina and Uruguay, as well as South Africa, Australia and New Zealand. It prefers water at 13 to 18 °C and lives on the shelf and around islands, from the surface down to hundreds of meters, in schools near the bottom or in midwater, which sometimes rise to the surface at night. It eats plankton crustaceans, squid and fish such as anchoveta and sardine. Typical size is 75 cm and up to about 6 kg. It is an important commercial fish, sold fresh, smoked and canned.
fun facts
- In English it is called barracouta or snoek; in South Africa it is a traditional fish.
- It is not related to the tropical Pacific seerfish, a mackerel of the genus Scomberomorus.
identification
Very elongated, compressed body, metallic dark blue, somewhat paler on the belly. Long, low first dorsal fin with 19 to 21 spines and a black membrane, followed by a short second dorsal fin and finlets. Large mouth with fang-like teeth. The lateral line runs along the back and drops suddenly below the end of the first dorsal fin. It is not the Pacific seerfish (Scomberomorus sierra), which is spotted and lives in warm waters, nor the scabbardfish, which has no tail.
where found
Does not occur in Brazil. In South America, southern Peru, Chile and Tierra del Fuego, Argentina and Uruguay; also in southern Africa, Australia and New Zealand.
Habitat: Continental shelf and around islands, in schools near the bottom or in midwater; comes close to shore after bait schools.
when to fish
best season
In south-central Chile, schools come closer to shore in summer, following anchoveta and sardine.
best time of day
Dawn and dusk. Rises to midwater and the surface at dusk and at night; stays deeper by day.
what affects the snoek
sensitivity The little bars show how much each factor affects this species. Five full: it feels it a lot.
cold and cold fronts
Prefers cold water, 13 to 18 °C; warm El Niño water drives it away.
atmospheric pressure
Rough sea prevents boat fishing.
moon
Dark nights help light fishing and shiny lures.
rain
Little effect at sea.
water level
Not applicable at sea.
noise
Not very sensitive while it is hunting.
wind
Strong wind makes slow corrico difficult.
tide
Currents at points and islands concentrate bait.
depth
10 to 80 m for boat fishing; shallower at dusk.
how to fish
- rod
- 7'0" to 8'0", 20 to 40 lb
- spinning / baitcasting reel
- spinning reel 5000 to 8000 or medium baitcasting reel
- line
- braid 30 to 50 lb
- leader
- fine steel leader or monofilament of 0.80 mm or more (cutting teeth)
- hook
- single hook 3/0 to 6/0 or reinforced treble hooks
lures
- metal jig, 60 to 150 g
- corrico spoon
- artificial squid
natural baits
- whole anchoveta or sardine
- squid strips
accessories
- long-nose pliers
- luvas
- bicheiro
tip from an angler
Use a steel or very heavy leader and be careful removing the hook: the teeth cut the hand easily.
rules for the snoek
Summary of the regulations we found, with the source for each. Rules change; before keeping or transporting fish, check with the state environmental agency.
Conservation: Not assessed by the IUCN, according to FishBase. We found no minimum size or closed season for amateur fishing in Chile, Peru, Argentina or Uruguay.
We found no species-specific rule beyond the region's general rules.
catch and release
catch and release Releasing the fish alive, quickly and with a wet hand. During a closed season it isn't always allowed: what the regulation says applies.
Hold it behind the head with a glove, away from the mouth, and remove the hook with long pliers. Release quickly, head first into the water.
in the kitchen
Firm, oily flesh; in Chile it is classically smoked (sierra ahumada) and also fried, baked and canned.
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.00427, b = 3.08; FishBase (estimativa bayesiana com dados da espécie e da subfamília, comprimento total); o tamanho máximo de 200 cm é citado pelo FishBase em comprimento padrão e destoa do peso máximo publicado (6 kg)). It's an average: a fat or lean fish can vary by 10% to 20%.
estimated weight
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sources and references
The season weights (months), the time of day and the sensitivities (cold, pressure, moon, wind, rain, tide, strong light, murky water and noise) are the app's editorial estimates, based on the literature below and on the field experience of anglers and guides. They are not official data nor a measurement made for this species, and they may vary by region and year. Closed seasons and legal rules appear in the rules section, with the norm and a link.
- scientific FishBase — Thyrsites atun (ficha da espécie)Names, distribution, biology, length-weight relationship, country list and references. Page checked on 13/10/2026. The country list includes the Falklands, left off the app's list.
- scientific IUCN Red List — Thyrsites atunSpecies not assessed by the IUCN, according to the FishBase entry (Red List, version 2025-2).
similar species
where each number comes from
The weather comes from three independent global models, cross-checked hour by hour: when they agree, confidence goes up; when they diverge, the band between them shows on the chart. Beyond 16 days, we use the GEFS ensemble of 31 simulations: if 20 of the 31 predict rain, the chance of rain is 65%. Sun and moon are calculated astronomically, with no uncertainty.
The index adds up, weighted for each species: time of day (species curve anchored to real sunrise and sunset), moon (transits, rise and set, phase), pressure (3 h trend and 24 h swing), water temperature (in rivers, estimated from air temperature; at sea, estimated by an ocean model), wind, rain, clouds, tide and the month in the species' cycle.
sources for this lookup
how accurate the forecast is
Accuracy measured in the reference project (4 regions, 93 days, forecast vs. observed): maximum temperature is off by 0.6 °C on average the next day and 1.7 °C at 7 days; rain of 5 mm or more is detected 76% of the time the next day and 57% at 7 days. Detection isn't everything: the false alarm rate isn't published here yet, and 93 days in 4 regions is still a small sample. We now also measure every day, at the app's destinations: