Sympterygia bonapartii · Arhynchobatidae · predator
Bottom skate of the South Atlantic, threatened in Brazil, where it occurs on the southern coast. Capture is prohibited in the country: if you hook it by accident, release it right away.
Also called: raia-emplastro-marmorada, emplastro, raya marmorada, smallnose fanskate
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 marbled emplastro skate is a skate of the family Arhynchobatidae, with a flattened body and a disc formed by the pectoral fins. It reaches 63 cm in disc width and lives on the shelf bottom, on sand and mud, down to 150 m, from Chile and from Rio Grande do Sul to Argentina. It is oviparous: the female lays oblong egg cases with pointed horns at the corners, and adults pair up and embrace during mating. It is bycatch of trawl nets and bottom longlines in the common fishing zone of Argentina and Uruguay. It is on the national list of threatened species as endangered, and catching it is prohibited in Brazil.
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 smallnose fanskate; in the meantime, see the similar species.
Bottom-dwelling skate with a wide, flattened fan-shaped disc, short rounded snout and a thin tail set apart from the disc. The dorsal pattern is marbled, as its Spanish name says. Its snout is smaller than that of the emplastro skate (Sympterygia acuta), which has a dark brown back. In Brazil it occurs only on the southern coast.
Southeast Pacific (Chile) and Southwest Atlantic, from Rio Grande do Sul to Rawson, Argentina. In Brazil it occurs only on the southern coast.
Habitat: Sand and mud bottom of the shelf, down to 150 meters.
coast
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: On the national list of threatened species as EN. Global IUCN assessment: NT.
The national list (Portaria GM/MMA nº 1.667/2026) classifies the species as EN. Under Portaria GM/MMA nº 1.666/2026 (art. 3), species listed as VU, EN and CR have full protection: capture, transport, storage, processing and sale are banned. If you hook one by accident, release it right away, with minimal handling.
Source: Portaria GM/MMA nº 1.666/2026, art. 3º, and Portaria GM/MMA nº 1.667/2026
Threatened species with capture prohibited in Brazil. If it comes on the line, keep the skate in the water whenever you can, remove the hook with long-nose pliers or cut the line close and release it right away. Avoid lifting it by the tail and watch the spines on the back and tail.
Length-weight relationship W = a·Lb (a = 0.00427, b = 3.09; 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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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.
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.
