banded butterflyfish
Chaetodon striatus · Chaetodontidae · omnivore
Butterflyfish of shallow reefs, with two wide dark bands on the flanks. It ranges from Massachusetts, USA, to Santa Catarina, Brazil, and is an aquarium fish.
Also called: borboleta, banded butterflyfish, isabelita rayada, parche rayado
- maximum
- 16 cm
- depth
- 5–20 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
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 banded butterflyfish
who is the banded butterflyfish
Butterflyfish of the family Chaetodontidae, living on shallow reefs, usually 5 to 20 m deep, alone or in pairs, and can reach 70 m. It reaches 16 cm and matures near 12 cm. Its body is short, high and compressed from the sides. It occurs in the western Atlantic, from Massachusetts, USA, to Santa Catarina, including the Gulf of Mexico and the Caribbean, and also at the St. Peter and St. Paul Rocks. It eats polychaete worms, coral polyps, crustaceans and mollusk eggs. In fishing it is bycatch, and it has aquarium value.
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 banded butterflyfish; in the meantime, see the similar species.
fun facts
- It forms groups of up to 20 individuals to feed on plankton, and sometimes cleans other reef fish, such as grunts, parrotfish and surgeonfish.
identification
Body with two wide dark bands on the sides, and a third band at the base of the soft part of the dorsal fin, which runs to the caudal peduncle. The median fins have wide dark bands on the edges, and the pelvic fins are black except for the spine. To tell it apart from Chaetodon sedentarius, which has a single wide bar on the peduncle, look at the side bands: Chaetodon striatus has two on the body.
where found
In Latin America it occurs on shallow reefs of Mexico, Cuba, Venezuela and Brazil, down to Santa Catarina, plus other Caribbean countries.
Habitat: Shallow coral reefs, 5 to 20 m, alone or in pairs.
coast
rules for the banded butterflyfish
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 poses no danger to the angler. Being small and of ornamental value, it should be handled with a wet hand and released quickly.
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.02239, b = 3.02; 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: Chaetodon striatus (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Chaetodon striatusNames 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: