cortez rainbow wrasse
Thalassoma lucasanum · Labridae · forage fish
Small, colorful wrasse of shallow reefs in the eastern Pacific, feeding on plankton and small invertebrates. It is almost never caught with a rod.
Also called: bodião-arco-íris-de-Cortés, arcoiris de Cortés, vieja de Cortés, viejita cabeza azul, Cortez rainbow wrasse
- maximum
- 15 cm
- depth
- 2–25 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 cortez rainbow wrasse
who is the cortez rainbow wrasse
The Cortez rainbow wrasse is of the family Labridae and reaches 15 cm. It lives in small groups over reefs, usually between 2 and 25 m deep, but is found down to 64 m, from the Gulf of California to Peru, including the Galápagos. It feeds on plankton floating in the water and small hard-shelled invertebrates. The species undergoes sex reversal, which is common among wrasses. It is not used as food and is of little interest to rod fishing, being sought mainly for the aquarium.
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 cortez rainbow wrasse.
fun facts
- The sex change is completed in 2 to 6 weeks.
identification
Small, spindle-shaped wrasse with bright colors, which justifies the name rainbow. One of its names in Peru, viejita cabeza azul, refers to its bluish head. The color changes over its life, because the species changes sex. It is usually seen in small groups over shallow reefs, generally between 2 and 25 m deep.
where found
Found in the eastern Pacific, from the Gulf of California to Peru, including the Galápagos Islands, on shallow reefs.
Habitat: Shallow reefs, with coral and rock, from 2 to 25 m deep.
rules for the cortez rainbow wrasse
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.
Small fish, no danger to anglers. Handle it with wet hands and release it quickly so as not to harm its skin.
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.01, b = 2.99; 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
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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: Thalassoma lucasanum (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Thalassoma lucasanumNames by country and language.
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: