french grunt
Haemulon flavolineatum · Haemulidae · predator
A yellow grunt that forms large schools over coral reefs and rocks. It has commercial use and is sold fresh, but it requires care because of ciguatera.
Also called: goibi, biquara, cambuba, ronco condenado, french grunt
- maximum
- 30 cm
- depth
- 0–60 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
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 french grunt
who is the french grunt
A fish of the family Haemulidae, reaching 30 cm. It occurs in the western Atlantic, from Bermuda, South Carolina and the northern Gulf of Mexico to Brazil, throughout the Caribbean and along the coast of Central America. It lives in large schools over rocky and coral reefs, often under overhangs or near branching corals, from 0 to 60 m deep. Juveniles are abundant in shallow seagrass near the shore. It feeds mainly on small crustaceans. In fishing it has commercial use, is sold fresh and serves as bait, with the caveat of ciguatera.
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 french grunt; in the meantime, see the similar species.
identification
Yellow over most of the body, paler on the belly, with a short, deep body. The easiest sign is the scales: those below the lateral line are large and set in oblique rows, much larger than those above. No other grunt in the region has enlarged scales below the lateral line, which separates this species from the rest.
where found
Western Atlantic, from Bermuda and South Carolina to Brazil, throughout the Caribbean and along the coast of Central America. In Brazil it is rarely recorded, especially along the Northeast coast.
Habitat: Rocky and coral reefs, in schools, 0 to 60 m deep.
coast
rules for the french grunt
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.
No dangerous spines. The concern is ciguatera: there are reports of poisoning from this species, so avoid eating specimens from reefs of doubtful origin.
in the kitchen
It is sold fresh in markets, but there are reports of ciguatera with this species, so avoid eating reef fish of doubtful origin.
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.01349, b = 3.0; 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: Haemulon flavolineatum (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Haemulon flavolineatumNames 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: