longspined porcupinefish
Diodon holocanthus · Diodontidae · predator
Porcupinefish with long spines that inflates like a balloon, of shallow reefs and sandy bottoms. There are reports of ciguatera, so it is not a fish to eat.
Also called: baiacu-balão, baiacu-de-espinho, balloonfish, pejerizo balón, pez erizo balón
- maximum
- 50 cm
- depth
- 2–35 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…
—
hour by hour
slide your finger or mouse over the chart to see each hoursee hour-by-hour table
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 longspined porcupinefish
who is the longspined porcupinefish
Porcupinefish of the family Diodontidae, with a short, deep body covered in long spines. It lives on shallow reefs and sand and mud bottoms, from 2 to 35 m, but can go down to 200 m. It reaches 50 cm, and its common size is around 15 cm. Juveniles sometimes stay in sargassum rafts, and adults live alone or in small groups. It eats mollusks, sea urchins, hermit crabs and crabs, mostly at night. It occurs in the western Atlantic, from Canada to Brazil, and in the eastern Pacific, from California to Colombia and the Galápagos. It is used in traditional Chinese medicine.
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 longspined porcupinefish; in the meantime, see the similar species.
fun facts
- It is used in Chinese medicine, according to the species references.
identification
Short, deep body covered in spines. It has a wide brown bar above and below each eye, plus another wide one on the nape. Adults have large dark blotches on the back, with small spots between them, and the fins have no spots; juveniles are spotted, with the spots more marked on the belly. To tell it apart from Diodon hystrix, which has only small spots, look at the large blotches on the back.
where found
In Latin America it occurs on reefs and shallow bottoms of the Caribbean, Mexico, Colombia, Ecuador, Brazil and Chile, plus the Galápagos.
Habitat: Shallow reefs and sand and mud bottoms, 2 to 35 m, with juveniles near sargassum rafts.
coast
rules for the longspined 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.
There are reports of ciguatera, so it is not for eating. The long spines call for care when handling: grip it with a protected hand and release it quickly.
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.05888, b = 2.8; 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
—
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 holocanthus (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 holocanthusNames 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: