Cynolebias porosus · Rivulidae · forage fish
An annual killifish endemic to Brazil, from the floodplains of the São Francisco River. It is sold for aquariums but is hard to keep in captivity.
Also called: peixe-anual-do-são-francisco, peixe-anual
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.
A fish of the family Rivulidae, the annual killifishes, freshwater and small. Reaches 15 cm. It is endemic to Brazil and lives in the floodplains of the São Francisco River, near the bottom, without migrating. Spawning takes place on the bottom, and the eggs take five to seven months to hatch, a long incubation typical of annual killifishes. It is sold for aquariums, although it is very hard to keep in captivity, and it also has commercial use. It is not a sport fish.
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 peixe-anual-do-são-francisco.
A small fish with a body compressed from side to side, a slightly pointed snout and a lower jaw that is not elongated. The base of the anal fin has scales, and the caudal and pectoral fins are rounded. The upper jaw is displaced downward, a trait that sets it apart from other species of the genus Cynolebias.
Endemic to Brazil: it lives in the floodplains of the São Francisco River.
Habitat: Floodplains of the São Francisco River, near the bottom.
native to the basins
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.
Allowed: Only exotic or hybrid species, 3 kg + 1 fish per day, with handline, rod, simple pole, or spinning or baitcasting reel. Nets prohibited. Keep the minimum distances from dams and reservoirs.
Source: Portarias IEF nº 154/2011 (São Francisco), 155/2011 (East) and 156/2011 (Grande/Paranaíba)
Allowed: Sport and guided fishing only in reservoirs, catch and release with barbless hooks (no keeping, transporting or eating). Subsistence: up to 5 kg per day, for household consumption only.
Allowed: Recreational fishing from a boat or from shore with handline, rod, spinning or baitcasting reel, up to 5 kg + 1 fish. Prohibited within 1,000 m of dams, waterfalls and rapids, and within 500 m of confluences. Floodplain lakes have a longer closed season (see next item).
Source: Portaria IBAMA nº 50/2007
Allowed: No fishing in the floodplain lakes during the period.
Source: Portaria IBAMA nº 50/2007
It has no spines or dangerous teeth. It is too small for rod fishing; if you catch one by chance, return it to the water promptly.
Length-weight relationship W = a·Lb (a = 0.01122, b = 3.04; 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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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.
