kelp perch
Brachyistius frenatus · Embiotocidae · forage fish
Small surfperch that lives among the giant kelp of the Mexican Pacific coast. It cleans other fish and forms large groups in summer.
Also called: perca-das-algas, mojarra sargacera, kelp perch
- maximum
- 22 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
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 kelp perch
who is the kelp perch
Surfperch of the family Embiotocidae, small, reaching 22 cm, and viviparous: the female carries the young until birth. It lives among giant kelp, especially in the kelp canopy, down to 30 m deep. It occurs from northern British Columbia, in Canada, to central Baja California, in Mexico, including Guadalupe Island. It eats small crustaceans that live on the kelp and also cleans other fish, removing parasites from their skin. In summer it forms large aggregations. It is commercially fished and appears in public aquariums.
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 kelp perch; in the meantime, see the similar species.
fun facts
- Cleans other fish, removing parasites from their skin.
identification
Small surfperch, olive or copper-toned above the lateral line, with dark pigment under each scale and a shine below it. The fins are pale or pinkish. On the same coast, the striped surfperch (Embiotoca lateralis) is larger, reaching 38 cm, and has blue stripes. The kelp perch reaches 22 cm.
where found
From northern British Columbia, in Canada, to central Baja California, including Guadalupe Island; in Latin America, only in Mexico, among giant kelp.
Habitat: Among giant kelp, mostly in the kelp canopy, down to 30 m deep.
rules for the kelp 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.
No recorded danger to anglers. It is harmless and small: release it quickly, with wet hands.
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.01318, b = 3.05; 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: Brachyistius frenatus (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Brachyistius frenatusNames 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: