swellshark
Cephaloscyllium ventriosum · Scyliorhinidae · predator
Small shark from rocky bottoms with algae, in the Pacific, that inflates its stomach with water or air. It is sometimes caught by recreational divers.
Also called: cação-inflado, gato hinchado, pejegato globo, swellshark
- maximum
- 110 cm
- depth
- 5–37 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
tap or drag on the chart to read each hour · on a keyboard, arrow keyssee 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 swellshark
who is the swellshark
The swell shark belongs to the family Scyliorhinidae and reaches 110 cm. It lives on the shelf and slope, from 5 to 457 m, but is most common between 5 and 37 m. It prefers rocky areas with algae, such as kelp forests. It feeds on bony fish, alive or dead, and probably on crustaceans. It is oviparous: the female lays eggs in pairs, and the embryos feed only on the yolk. At rest it forms groups, sometimes one on top of another. It has no commercial interest, and can live for several years in an aquarium.
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 swellshark.
fun facts
- It can live for several years in an aquarium, and the female can lay eggs in captivity.
identification
Small, elongated shark of the family Scyliorhinidae. The trait that gives the species its name is that it can inflate its stomach with water or air and become rounded. It lives close to rocky bottoms with algae, and at rest it forms groups, sometimes one on top of another. The habit of inflating its stomach is what most helps separate it from other small sharks of the region.
where found
In Latin America, it occurs in southern Mexico and central Chile, on rocky and algae-covered shelf bottoms. To the north, it ranges from central California to the Gulf of California.
Habitat: Rocky bottoms with algae, on the shelf, 5 to 37 m deep.
when to fish
best time of day
Nighttime. According to the source, it is nocturnal and feeds at night.
rules for the swellshark
Summary of the regulations we found, with the source for each. Rules change; before keeping or transporting fish, check with the state environmental agency.
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.
Shark with no danger to whoever catches it. Handle it with care, wear a glove if needed, and release it with minimal handling.
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.00269, b = 3.21; 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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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: Cephaloscyllium ventriosum (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Cephaloscyllium ventriosumNames by country and language.
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: