A primitive shark with seven gill slits and a single dorsal fin, all spotted. Critically Endangered in Brazil. In Argentina it is the gatopardo, with mandatory release in Buenos Aires and Río Negro and Natural Monument status in Chubut.
Also called: cação-bruxa, tubarão-de-sete-guelras, gatopardo
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.
location
Sample location: choose yours to see the forecast for where you fish.
period
Reading the weather across 3 global models and 31 simulations…
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index Score from 0 to 100 for the fishing conditions of each hour. It reads weather, sun, moon, tide and the species' habits. It doesn't promise fish: it tells you when the water is on your side. 0–24 poor · 25–44 fair · 45–64 good · 65–84 very good · 85–100 excellent.
today
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confidence —
confidence How much you can trust the weather forecast for the day. It drops with distance and when the models disagree. It is not the chance of catching fish.
models and trend Up to 16 days, three global weather models (the European ECMWF, the American GFS and a high-resolution blend) read hour by hour; when they disagree, the light band on the chart widens. Beyond that it's a trend: 31 runs of the American GEFS model. Confirm when it's 1 week out.
window Consecutive hours with the index near the day's peak and no danger alert. It is the time to have the bait in the water.
hour by hour
tap or drag on the chart to read each hour · on a keyboard, arrow keys
see hour-by-hour table
why this index at —?
next 7 days
choose the day
chart: bar height = day's index · line = variation between models · striped = trend · fainter = less confidence
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.
4-week calendar
the fishing month at a glance
plan a trip
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.
the species
everything about the broadnose sevengill shark
overview
who is the broadnose sevengill shark
The gatopardo (cação-bruxa) belongs to an ancient shark family, with seven gill slits on each side and a single dorsal fin set far back on the body. It lives in temperate waters, shallow bays, estuaries and the continental shelf, and is an apex predator: it eats fish, rays, other sharks and even sea lions. In the South Atlantic it occurs from southern Brazil to northern Argentina and uses shallow bays as nurseries, such as Anegada Bay near San Blas. In Brazil it is rare and Critically Endangered. In Argentina, the gatopardo is one of the trophies of shark fishing at San Blas and San Matías Gulf, always with release, and Chubut declared it a Natural Monument in 2025.
fun facts
It has seven gill slits on each side, a feature of a very ancient shark lineage.
It can live almost 50 years.
Newborns appear in Anegada Bay, a sign that the bay works as a nursery.
how to recognize it
identification
Seven gill slits on each side (most sharks have five) and a single dorsal fin, small and set far back, above the anal fin. Broad head, short rounded snout, small eyes. Silver-gray to brown body, covered in black dots and some white ones. Long tail. The mangona and the bronze whaler have five gill slits and two dorsal fins.
In Brazil, rare, on the southern coast. In the southwestern South Atlantic it ranges from southern Brazil to northern Argentina, notably Anegada Bay and San Blas Bay (Buenos Aires), the Bahía Blanca estuary and the gulfs of Río Negro and Chubut. In the Pacific, from Canada to Chile.
Habitat: Shallow bays, estuaries and tidal channels, beaches and the continental shelf; pups in shallow bays.
coast
South Coastcoastalshelf
states
Santa Catarina, Rio Grande do Sul
calendar and clock
when to fish
best season
time of yearbest: Nov–Mar
JanFebSeaAprMayJunJulAugSepOctNovDec
Estimate: in Argentine Patagonia, release-based fishing is concentrated in spring and summer. In Brazil it is rare, with no defined season for anglers.
best time of day
Daytime, with peaks at dawn and dusk. Feeds by day in channels with the tide running, and also at dusk and at night.
weather, water and behavior
what affects the broadnose sevengill shark
sensitivity The little bars show how much each factor affects this species. Five full: it feels it a lot.
cold and cold fronts
A temperate-water species; tolerates cold water.
atmospheric pressure
Cold fronts bring wind and rough seas that prevent fishing in the bays.
moon
Spring tides speed up the current in the bay channels.
rain
Not very relevant.
water level
Not applicable at sea.
noise
Not very sensitive.
wind
Strong wind stirs up the shallow bays and keeps boats from leaving.
tide
In the San Blas channels, the running tide is what drives the fishing.
depth
Usually down to about 80 m; pups in the shallows of the bays.
4/0 to 6/0 baitcaster or large casting spinning reel
line
monofilament of at least 0.70 mm (required in Buenos Aires) or 80 lb braided line
leader
1 to 1.5 m wire leader plus heavy monofilament
hook
circle hook 12/0 to 14/0 with the barb flattened; single hook only, no tandem rigs
natural baits
cut bait or half a fish on the bottom (mullet, pescadilla, mackerel), where catch and release is permitted
accessories
stopper float 25 cm above the hook
cutting pliers for steel cable
long hook remover
luvas
tip from an angler
In Brazil, catch is prohibited. In Argentina it is always release: keep the fight short, don't bring the gatopardo aboard, and cut the leader close to the mouth if the hook is deep.
what the law says
rules for the broadnose sevengill shark
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: Catch prohibited throughout Brazil. Global: Vulnerable (IUCN, February 8, 2020).
Threatened species (CR): catch prohibited in Brazil
catching, transport, holding and trade prohibited
The gatopardo (cação-bruxa, Notorynchus cepedianus) is on the national list as Critically Endangered (CR) (it was already on the previous list, Portaria MMA 148/2022). Ministerial Ordinance GM/MMA 1.666/2026 (art. 3) prohibits catch, transport, storage, possession, processing and trade throughout Brazil. Anyone who hooks one by chance must release it alive immediately (art. 3, § 4). The rule does not authorize targeted fishing, even with release: in Brazil, do not seek this species.
Finning prohibited: shark only whole, with its fins
fins naturally attached to the body
In Brazil, finning is prohibited (cutting off the fins and discarding the body). Every shark or ray landed must arrive with its fins attached to the body; it is prohibited to carry on board an animal without fins or with loose fins, and to transfer sharks between vessels. It applies to any shark that may be kept.
Buenos Aires (AR): mandatory release of large coastal sharks
mandatory release; killing prohibited
On the Buenos Aires Province coast (and in the Plata, Bahía Blanca and Mar Chiquita estuaries), escalandrún, bacota, gatopardo, cazón and hammerheads are "reserved directed fishing": release is mandatory, and killing is prohibited even for incidental catch. Gear rules: one rod per angler on a boat and two from shore; single-hook rigs only (tandem rigs prohibited); circle or biodegradable hook 12/0 to 14/0 with the barb flattened; a stopper float 25 cm above the hook is recommended on bottom lines, along with nylon line of at least 0.70 mm. Gaffs are prohibited. Remove the hook only if there is no risk; otherwise cut the line close to the hook, avoiding lifting the shark out of the water. From Pehuén-Có to the mouth of the Río Negro (including the Bahía Blanca estuary, Anegada Bay and San Blas), a permanent closed season also applies to artisanal and commercial fishing for escalandrún, bacota, gatopardo and cazón (Disposition 55/2008).
Río Negro (AR): mandatory release (Law 5.706/2023)
mandatory release; killing prohibited
In Río Negro Province marine sport fishing (San Matías Gulf, El Cóndor, Bahía Creek), the gatopardo (Notorynchus cepedianus) is under a special protection regime: killing during capture is prohibited and release is mandatory. In boat fishing targeting sharks: one hook per line (tandem rigs and tartuna-type galvanized hooks prohibited), a "J" hook with the barb filed or flattened, or a circle hook. A specimen on board only with scientific authorization.
Chubut (AR): the gatopardo is a provincial Natural Monument
hunting, catch and trade prohibited; release aliveconfirm with the agency
In April 2025 the Chubut Legislature unanimously approved the Natural Monuments law, which includes the gatopardo among seven protected species. According to the local press, the law prohibits hunting, catch and trade, and requires the animal to be returned alive to the sea. We did not find the law number or the text in the Official Bulletin: confirm with the Chubut Fisheries Secretariat before fishing.
1 specimen per angler per day (counts as 5 against the quota of 10)
In recreational sport fishing in Mexican saltwaters, the limit for sharks is one specimen per angler per day, which counts as five toward the total limit of ten fish. Fish caught in sport fishing may not be sold. Catch and release does not count toward the limit: prefer releasing.
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.
In Brazil, only release of incidental catch. In Argentina: leave it in the water, head facing the current, remove the hook with a dehooker or cut the line close to the mouth, and release it within a few minutes. Don't hold it by the gills.
in the kitchen
Catch and trade prohibited in Brazil; in Argentina, killing is prohibited in sport fishing.
calculator
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.00224, b = 3.15; FishBase (estimativa bayesiana para a família e o formato do corpo, comprimento total)). 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 seasonal weights (months), time of day and 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 field experience of anglers and guides. The months indicate the time of year when the angler usually finds the species near the coast, not a catch season. They are not official data or measurements made for this species and may vary by region and year. Legal rules appear in the rules section, with the regulation and link.
officialPortaria GM/MMA nº 1.666, de 27 de abril de 2026 — regras de proteção das espécies ameaçadas da lista nacionalArt. 3: full protection for VU, EN and CR species; § 4: incidental catch with immediate release of the live animal. The 180-day transition rule for species newly added to the list was verified from official summaries (Fiperj) and technical sources; the DOU (Brazil's Official Gazette) page did not open during verification.
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:
where are you going fishing?
Your location is saved only on this device and feeds the forecast, the map and the "today" on the home page.
