longtail southern cod
Patagonotothen ramsayi · Nototheniidae · forage fish
A notothenia restricted to the Patagonian shelf, in the southwestern Atlantic, in waters of Argentina, Uruguay and Chile. Exploited by commercial fishing and of no sport interest.
Also called: nototênia-de-Ramsay, nototenia, nototenia coluda, longtail southern cod
- maximum
- 44 cm
- depth
- 50–500 m
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 longtail southern cod
who is the longtail southern cod
A fish of the family Nototheniidae, with a spindle-shaped body and a rounded tail, which lives near the bottom of the Patagonian shelf, between 50 and 500 m. It reaches 44 cm, much less than the Patagonian toothfish of the same area. It feeds mainly on gelatinous plankton and plankton crustaceans, near the bottom. Its range is limited to the Patagonian shelf, in the southwestern Atlantic, in waters of Argentina, Uruguay and Chile. It is exploited by commercial fishing and is of little importance for sport fishing.
Essential profile. Identification, where it occurs and rules, with data from FishBase and the cited regulations. Season, time of day, technique and bait are added once we have a good source for the longtail southern cod; in the meantime, see the similar species.
identification
A spindle-shaped fish of normal shape, with a rounded caudal fin and a long dorsal fin. It lives only on the Patagonian shelf, so the habitat helps identify it. The merluza negra (Patagonian toothfish, Dissostichus eleginoides), from the same region, reaches 215 cm, much bigger. In practice, the size of up to 44 cm and the depth band of 50 to 500 m are the surest clues.
where found
Restricted to the Patagonian shelf, in the southwestern Atlantic, in waters of Argentina, Uruguay and Chile.
Habitat: Patagonian shelf, 50 to 500 m deep, near the bottom.
rules for the longtail southern cod
Summary of the regulations we found, with the source for each. Rules change; before keeping or transporting fish, check with the state environmental agency.
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.
The spines are not dangerous. It lives in deep bottoms, so ascent causes barotrauma; if it is released, do it carefully.
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.00589, b = 3.22; FishBase (relação peso-comprimento bayesiana, estimativa)). It's an average: a fat or lean fish can vary by 10% to 20%.
estimated weight
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sources and references
Essential profile: size, length-weight, depth, countries and conservation come from FishBase and the cited regulations, and the texts were written from those sources. Season, time of day, sensitivities, technique and baits and lures are not included yet, because we did not find a good source for this species.
- scientific FishBase: Patagonotothen ramsayi (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Patagonotothen ramsayiNames by country and language.
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: