silvery john dory
Zenopsis conchifer · Zeidae · predator
Silvery fish that forms small schools over mud bottoms, from the Brazilian coast to Argentina, and feeds on fish and squid.
Also called: são-pedro, galho, san pedro, silver john dory
- maximum
- 80 cm
- record/max.
- 3.2 kg
- depth
- 150–300 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
slide your finger or mouse over the chart to see each hoursee 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 silvery john dory
who is the silvery john dory
Fish of the family Zeidae, with a short, deep body, reaching 80 cm and weighing up to 3.2 kg. It lives near the bottom or in midwater, over mud bottoms, usually between 150 and 300 m. It forms small schools and often appears in coastal waters. It feeds on fish and squid. It occurs from Venezuela and Colombia to the coasts of Brazil and Argentina, through the Guianas. It has a commercial fishery.
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 silvery john dory.
identification
Silvery body, short and deep, with a dark spot on the flank, just behind and slightly above the base of the pectoral fin. The membranes of the spiny dorsal, pectoral, pelvic and caudal fins are dark. To recognize it, look at this flank spot and the dark color of the fins.
where found
In Latin America, it occurs from Venezuela and Colombia to the coasts of Brazil and Argentina, passing through the Guianas and Trinidad.
Habitat: Mud bottoms of the shelf and slope, from 150 to 300 m, near the bottom or in midwater.
coast
rules for the silvery john dory
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 on the Brazilian national list (Ministerial Ordinance GM/MMA No. 1.667/2026).
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.
No danger to the angler. As it lives in deep bottom waters, it can suffer barotrauma if brought up quickly to the surface, so release it with care.
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.01349, b = 2.93; FishBase (relação peso-comprimento bayesiana, estimativa da própria espécie)). 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: Zenopsis conchifer (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Zenopsis conchiferNames by country and language.
- official Portaria GM/MMA nº 1.667, de 27 de abril de 2026: Lista Nacional Oficial de Espécies da Fauna Ameaçadas de Extinção (peixes e invertebrados aquáticos)The species is not on the list. Checked in the DOU of April 28, 2026.
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: