Hyporthodus niveatus · Epinephelidae · predator
Deep-water grouper of the Southeast and South. Vulnerable species: only fish 45 cm and up may be kept, and the fleet has a closed season in September and October.
Also called: cherne-verdadeiro, cherne, cherne-pintado, serigado-cherne, chernote
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…
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.
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.
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.
The snowy grouper is an epinephelid of the grouper family, from deep waters: it lives on rocky bottoms of the outer shelf and slope, usually 100 to 200 m, from the North American Atlantic coast to southern Brazil. Juveniles can occur closer to shore. It eats fish, snails, squid, and crabs. It grows slowly and can live nearly 30 years, which makes it vulnerable to bottom line and longline fishing. It is on the national list as Vulnerable and has a recovery plan: Portaria Interministerial 40/2018 allows catching and keeping only fish 45 cm and up, and created a closed season for the fleet from Sep 1 to Oct 31 between 100 and 600 m in the Southeast and South. Below the size limit, release it. Because of its depth, it suffers badly from barotrauma.
Robust grouper, dark brown to grayish brown, covered with white spots in rows that disappear in large adults. Black saddle mark on the tail base that extends below the lateral line, and a dark edge on the spiny dorsal fin. Juveniles have pale yellow caudal and pectoral fins. Differs from the true grouper and the badejo-quadrado by the black saddle on the tail base and the white spots.
In Brazil, mainly from Espírito Santo to Santa Catarina, on deep rocky bottoms of the outer shelf and slope.
Habitat: Rocky bottoms, submerged reefs, and breaks of the outer shelf and upper slope; juveniles in shallower bottoms.
coast
states
Espírito Santo, Rio de Janeiro, São Paulo, Paraná, Santa Catarina
Fished all year, respecting the fleet's closed season in September and October.
Any time. At great depth, the time of day matters little.
Lives in cold bottom water.
A cold front brings rough seas.
Small effect.
No effect at depth.
Does not depend on water level.
Not very sensitive beyond 100 m.
Strong wind prevents staying over the submerged reef.
Strong current makes it hard to keep the bait on the rock.
100 to 200 m for most catches.
lures
natural baits
accessories
Measure before you decide: below 45 cm, release it with a descending device.
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: Recovery plan (Portaria MMA 227/2018) with rules in PI SG-PR/MMA 40/2018, under review by Portaria 1.666/2026 (art. 11). Global assessment: VU (IUCN).
Catch, retention, transport, and sale are allowed only for specimens with a total length of 45 cm or more. Outside the limits of the ordinance, directed fishing is prohibited, and fish caught by chance must be released alive or discarded on the spot, with a record.
Source: Portaria Interministerial SG-PR/MMA nº 40/2018, arts. 2º and 4º, subparagraph a
From September 1 to October 31, fishing between 100 and 600 m depth is prohibited on the Southeast and South coast for the fishing modes listed in the ordinance (INI MPA/MMA 10/2011). On-board retention and landing of snowy grouper are tolerated only until September 5.
Source: Portaria Interministerial SG-PR/MMA nº 40/2018, art. 6º
The species remains Vulnerable on the 2026 list. Its use depends on the recovery plan (Portaria MMA 227/2018) and the rules of PI 40/2018. Portaria GM/MMA 1.666/2026 ordered a review of the plans for species already on the list, and the earlier rules remain in force during the review. Confirm before keeping any fish.
Source: Portaria GM/MMA nº 1.666/2026, art. 11; PI SG-PR/MMA nº 40/2018, art. 1º
It almost always comes up with barotrauma (stomach everted, bulging eyes). To release it, use a descending device to take the fish back to the bottom; puncturing the swim bladder without the right technique kills it.
White, firm, highly prized flesh. May only be kept from 45 cm.
Length-weight relationship W = a·Lb (a = 0.01549, b = 3.04; FishBase (estimativa bayesiana, comprimento total)). It's an average: a fat or lean fish can vary by 10% to 20%.
estimated weight
—
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.
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.
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:
Your location is saved only on this device and feeds the forecast, the map and the "today" on the home page.
