grass porgy
Calamus arctifrons · Sparidae · predator
Small porgy of the seagrass beds of the Gulf of Mexico, with a dark spot behind the gill, sold fresh and frozen.
Also called: peixe-pena-do-capim, pez de pluma, pluma negra, grass porgy
- maximum
- 25 cm
- depth
- 1–22 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 grass porgy
who is the grass porgy
The seagrass porgy belongs to the family Sparidae and reaches 25 cm. It lives in shallow seagrass beds, from near the beach to at least 22 m, from southern Florida to Louisiana, United States, and in the eastern Gulf of Mexico. In Latin America it occurs only in Mexico. It mainly feeds on invertebrates. Small fish form small groups. It is commercially fished, sold mainly fresh and frozen, and sometimes used as bait.
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 grass porgy; in the meantime, see the similar species.
identification
Small porgy with a spiny dorsal fin and a compressed body. It has a dark spot, larger than the pupil, on the lateral line just behind the gill opening, which often shows and is the main sign. It may be confused with the canhanha (Archosargus rhomboidalis), which also has a dark spot behind the gill, but the canhanha is larger, reaching 33 cm, and lives in mangroves.
where found
In Latin America it occurs only in Mexico, in the Gulf of Mexico.
Habitat: Shallow seagrass beds, 1 to 22 m.
rules for the grass porgy
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.
It poses no danger to the angler. Being small, it can be released right away.
in the kitchen
It is sold mainly fresh and frozen.
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.02089, b = 2.95; FishBase (relação peso-comprimento bayesiana, estimativa pelo gênero e formato do corpo)). 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: Calamus arctifrons (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Calamus arctifronsNames 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: