Rhizoprionodon porosus · Carcharhinidae · predator
Small, slender shark of bays, estuaries and beaches, which enters rivers. Vulnerable worldwide and not on the national list, but easily confused with protected sharks: when in doubt, release it.
Also called: cação-rabo-seco, tubarão-rabo-seco, rabo-seco, cação-frango, Caribbean sharpnose shark
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 Caribbean sharpnose shark is a small shark of the family Carcharhinidae, up to 1.1 m and about 7 kg. It is common in bays and estuaries, where it enters rivers, and it also appears in open sea down to 500 m, though it almost always stays within 100 m. It eats small bony fish, including wrasses, and also sea snails, squid and shrimp. The female has 2 to 6 pups of about 31 to 39 cm. It is eaten locally, sold salted or frozen, and also made into fishmeal. IUCN classifies it as Vulnerable. In Brazil it is not on the national list, but there are protected sharks that look similar.
Small, slender shark with a long, pointed snout, greyish-brown on the back and pale below. It belongs to the genus Rhizoprionodon, the sharpnose sharks. It is easily confused with the Brazilian sharpnose shark (R. lalandii), which occurs on the same coast, and with the smalltail shark (Carcharhinus porosus), which is threatened and has an almost identical scientific name: the smalltail is in a different genus, larger and more robust as an adult. FishBase notes that the separation between the Caribbean sharpnose and R. terraenovae is still debated. When in doubt, release it.
Western Atlantic: from the Caribbean, including the Bahamas, to Uruguay. In Brazil, along the whole coast, in bays, estuaries and beaches, with river entries. Outside Brazil, FishBase lists the Bahamas, Belize, Colombia, Cuba, the Dominican Republic, French Guiana, Guyana, Honduras, Haiti, Jamaica, Nicaragua, Panama, Puerto Rico, Suriname, Trinidad and Tobago, Uruguay and Venezuela.
Habitat: Bays, estuaries and beaches, with river entries; in open sea down to 500 m, but almost always within 100 m.
coast
Estimate: present year-round in the tropics, closer to shore in warm months.
Any time. No fixed time in the sources we checked (estimate): hunts by day and by night, with more activity in shallow water when the tide rises.
Cold water keeps the shark away from shallow areas and bays.
Little known direct effect.
Spring tides move more water through the inlets and concentrate prey.
Heavy rain lowers estuary salinity and can push the shark out of the river mouth.
Not applicable at sea.
Not very sensitive to noise, but it flees motorboats in very shallow water.
Rough surf on the beach makes casting difficult.
The incoming tide carries the shark into bays and channels.
Usually 0 to 100 m.
natural baits
accessories
Being small and sharp-toothed, it is fished on the bottom with natural bait and a short steel leader. Release it in the water; before keeping any shark, make sure it is not a smalltail shark or another species on the list.
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 (Portaria GM/MMA nº 1.667/2026). IUCN global assessment: VU (A2d, Jun 21, 2019). General recreational fishing rules and the finning ban apply.
In Brazil, finning is banned: catching sharks and rays and keeping only the fins, discarding the body (art. 3). Sharks and rays landed must arrive with all fins naturally attached to the body; carrying an animal aboard without fins or with loose fins, and transferring sharks and rays between fishing vessels, is prohibited. This applies to any species that may be retained.
The Caribbean sharpnose shark (Rhizoprionodon porosus) is not on the national list, but several Carcharhinus sharks of similar general appearance are protected: smalltail shark (Carcharhinus porosus, CR, an almost identical scientific name), blacknose shark (C. acronotus, VU), night shark (C. signatus, EN) and spinner shark (C. brevipinna, VU, from late Oct 2026). If you are not sure of the species, release it.
Source: Portaria GM/MMA nº 1.667/2026 (national list) and Fiperj poster on Portarias 1.666 and 1.667/2026
In 2021 Colombia stopped treating marine sharks and rays as fishery resources and began treating them as hydrobiological resources. The recitals of Decree 281/2021 state that they may not be extracted for commercial or sport purposes, and the decree created an environmental protection plan. Later AUNAP rules addressed incidental catch in artisanal fishing; we did not check the consolidated text. When in doubt, release them into the water.
Executive Decree 9/2026 (art. 19) bans, throughout the national territory and in sport, recreational, or tourism fishing, the catch, retention, handling for recreational purposes, use, and landing of sharks and rays (subclass Elasmobranchii). If one is hooked by accident, it must be released immediately, without taking it fully out of the water and without unnecessary handling. It is also prohibited to promote them as targets in tournaments (art. 19) and to sell the catch (art. 20). The decree takes effect six months after its promulgation on June 10, 2026 (art. 40), around Dec 10, 2026, and repeals Resuelto ADM/ARAP 002/2012 (art. 39). Confirm the date with ARAP.
The official fishing guide of the Bahamas states that shark fishing is not allowed, that sharks have been protected since a 2011 amendment, that they may only be taken under special permits for very specific purposes, and that a shark hooked in any fishing must be released unharmed. The page does not cite the number of the rule.
Short fight and release with the shark in the water. Hold it with a glove at the base of the tail and under the belly, never by the gills, and cut the line close to the mouth if the hook is deep. Revive it facing the current before letting go.
Eaten salted or frozen where subsistence and commercial fishing occur. Sharks retain urea in their flesh: bleed and gut it quickly. Vulnerable worldwide: prefer to release it, especially with protected look-alike sharks.
Length-weight relationship W = a·Lb (a = 0.00219, 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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The season factors (months), the time of day, and the sensitivities (cold, pressure, moon, wind, rain, tide, strong light, murky water, and noise) are editorial estimates by the app, based on the literature cited below and on field experience of anglers and guides. They are not official data or measurements made for this species and may vary by region and year. Closed seasons and legal rules appear in the rules section, with the standard and link. The months indicate when anglers usually find the species near the coast, not a catch season.
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.
