spotted porcupinefish
Diodon hystrix · Diodontidae · predator
Porcupinefish with a body covered in long spines, which inflates. It can be venomous if eaten, so it is not fit for eating.
Also called: baiacu-de-espinho, graviola, pez erizo, puercoespín, spotted porcupinefish
- maximum
- 91 cm
- record/max.
- 2.8 kg
- depth
- 3–20 m
the right time
to be on the water
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…
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hour by hour
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why this index at —?
choose the day
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.
the fishing month at a glance
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.
everything about the spotted porcupinefish
who is the spotted porcupinefish
Porcupinefish of the family Diodontidae, with a robust body covered in long, sharp spines that lie flat when the fish is not inflated. It reaches 91 cm and 2.8 kg, but its common size is around 40 cm. It lives on lagoon and open-sea reefs, down to at least 50 m, and hides in caves and holes in shallow reefs. Juveniles, up to about 20 cm, are pelagic, and adults live on the bottom, alone and nocturnal. It eats sea urchins, gastropods and hermit crabs. It occurs in all tropical seas; in the western Atlantic it ranges from Massachusetts to Brazil. It is not usually eaten.
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 spotted porcupinefish; in the meantime, see the similar species.
fun facts
- In an aquarium, one specimen lived 10 years.
identification
Grayish-brown body with small black spots, no large blotches, and a white belly surrounded by a dark band. The spines are long, and the teeth join in each jaw, without a gap in the middle, forming a beak. To tell it apart from Diodon holocanthus, which has large dark blotches on the back and brown bars on the head, check whether the fish has only small spots, including on the fins.
where found
In Latin America it occurs in the Atlantic, from the Caribbean to Brazil, and in the Pacific, from Mexico to Chile and the Galápagos, on reefs and in lagoons.
Habitat: Lagoon and open-sea reefs, down to at least 50 m, with caves and holes.
coast
when to fish
best time of day
Nighttime. According to the species source, it is solitary and nocturnal, feeding on hard-shelled animals at night.
rules for the spotted porcupinefish
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.
catch and release
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.
It is not for eating, because it can be venomous. The long spines and the beak of fused teeth call for care when handling; it is best to release it quickly.
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.08913, b = 2.77; 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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sources and references
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.
- scientific FishBase: Diodon hystrix (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Diodon hystrixNames by country and language.
- official Portaria GM/MMA nº 1.667, de 27 de abril de 2026: Lista Nacional Oficial de Espécies da Fauna Ameaçadas de Extinção (peixes e invertebrados aquáticos)The species is not on the list. Checked in the DOU of April 28, 2026.
similar species
where each number comes from
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.
sources for this lookup
how accurate the forecast is
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: