barred knifejaw
Oplegnathus fasciatus · Oplegnathidae · predator
Deep-bodied fish with dark bands, from shallow rocky reefs, caught on rod and also farmed. Its main range is the northwest Pacific, with a record from Chile.
Also called: sargo-faixado, sargo, barred knifejaw
- maximum
- 80 cm
- record/max.
- 6.4 kg
- depth
- 1–10 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
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 barred knifejaw
who is the barred knifejaw
The barred knifejaw is a reef fish of the family Oplegnathidae, with a short, deep body. It lives on shallow rocky coastal reefs, between 1 and 10 m deep, and has a benthopelagic habit, meaning it stays near the bottom but also rises into the water column. It reaches 80 cm and 6.4 kg. It is commercially fished, farmed in aquaculture and targeted by rod anglers. In Latin America it is recorded from Chile, but its main range is the northwest Pacific. It has been introduced to the Mediterranean.
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 barred knifejaw.
fun facts
- Juveniles associate with drifting algae near reefs.
identification
A fish with a short, deep body and dark bands crossing the body, as the name suggests. Adults live on shallow rocky reefs, from 1 to 10 m. Juveniles associate with drifting algae near reefs. The short, deep shape is the first sign for recognizing it, and the dark bands complete the identification.
where found
In Latin America, the species is recorded from Chile, but its main range is the northwest Pacific, in Japan, Korea and Taiwan, as well as Hawaii. It has been introduced to the Mediterranean.
Habitat: Rocky coastal reefs, 1 to 10 m deep.
rules for the barred knifejaw
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.
Not dangerous. Release it carefully, without squeezing the body, and use pliers to remove the hook.
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.01995, b = 3.01; 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: Oplegnathus fasciatus (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Oplegnathus fasciatusNames 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: