humpback grunt
Microlepidotus brevipinnis · Haemulidae · predator
Blue-grey grunt of coastal waters in the eastern Pacific, which mainly appears as bycatch in nets.
Also called: roncador-perolado, ronco bronceado, ronco rayadillo, humpback grunt
- maximum
- 40 cm
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 humpback grunt
who is the humpback grunt
The pearly grunt belongs to the family Haemulidae, the grunts. It reaches 40 cm, and its common size is 30 cm. It lives in coastal waters of the eastern Pacific, from the Gulf of California to Panama, with a record also from Ecuador, between the bottom and midwater. It forms schools over the coastal sea and mainly appears as bycatch in nets. The body is elongated and compressed, with a small, terminal mouth. Because it is caught together with other species, it is of little importance to sport fishing.
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 humpback grunt; in the meantime, see the similar species.
identification
Elongated, compressed body, with a small, terminal mouth. The color is blue-grey, and each scale has a grey pearly dot, forming lines that follow the rows of scales. The fins are yellowish. It can be confused with Orthopristis chalcea, which also has golden lines on the flanks, but its lines are wavy and gold or copper colored. Xenichthys xanti, from the same coast, has golden stripes and very large eyes.
where found
Found in the eastern Pacific, from the Gulf of California to Panama, in coastal waters, with a record also from Ecuador.
Habitat: Coastal waters, between the bottom and midwater, in schools.
rules for the humpback 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.
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 danger to anglers. If released, return it to the water carefully.
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.0166, b = 3.02; 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: Microlepidotus brevipinnis (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Microlepidotus brevipinnisNames by country and language.
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: