shiner perch
Cymatogaster aggregata · Embiotocidae · omnivore
Small surfperch of bays, estuaries and calm waters of the Mexican Pacific. It forms schools near piers and pilings and is caught in sport fishing.
Also called: perca-brilhosa, mojarra brillosa, shiner perch
- maximum
- 20 cm
- depth
- 1–146 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 shiner perch
who is the shiner perch
Surfperch of the family Embiotocidae, with a deep, compressed body, large scales and silvery tones. It reaches 20.3 cm, and the common size is 11.5 cm. It lives in bays, in calm waters, near piers, pilings and seagrass, and enters estuaries and brackish water. It occurs from Alaska to San Quintín Bay, in Mexico. It forms loose schools. Juveniles eat copepods, and adults eat small crustaceans, mollusks and algae. It is viviparous: the female carries the young. It is of interest to sport fishing and is 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 shiner perch; in the meantime, see the similar species.
fun facts
- Breeding males turn almost black and develop fleshy lobes on both sides of the anal fin.
identification
Surfperch with a deep, compressed body, large scales and a silvery color, with a greenish or grayish back. It has longitudinal rows of fine black dots and three pale yellow vertical bands on the flanks. Males in breeding season turn almost black. On the same coast, the striped surfperch (Embiotoca lateralis) has blue stripes, and the white seaperch (Phanerodon furcatus) has yellowish fins.
where found
From Alaska to San Quintín Bay, in northern Baja California; in Latin America, only in Mexico, in bays, estuaries and calm waters.
Habitat: Bays, estuaries and calm waters near the coast, mostly shallow, among algae and piers.
rules for the shiner perch
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 has no venomous spines and is safe to handle. If it is released, let it go in the water quickly.
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.0195, b = 2.97; 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: Cymatogaster aggregata (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Cymatogaster aggregataNames 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: