bay blenny
Hypsoblennius gentilis · Blenniidae · omnivore
Small blenny of shallow waters and the intertidal zone of the Mexican Pacific. It is territorial, is almost never caught with a rod and poses no danger.
Also called: blênio-de-baía, borracho de bahía, bay blenny
- maximum
- 15 cm
- depth
- 0–25 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 bay blenny
who is the bay blenny
Small, elongated fish of the family Blenniidae, living in shallow waters and the intertidal zone, usually down to 10 m, in shelters. It reaches 15 cm and 7 years of age. It is territorial and feeds on small invertebrates and bottom algae. The male guards the eggs, which stick to the walls of the shelter. It occurs in the Mexican Pacific, from Baja California to the Gulf of California. It is taken for the trade and the aquarium, but almost never with a rod.
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 bay blenny.
identification
Small, elongated fish of the family Blenniidae, living in shallow waters with shelters. Like blennies in general, it has no scales and a rounded head with eyes on top. It reaches 15 cm. Its territorial life, always close to its shelter, helps identify it in the field.
where found
In Mexico it occurs in the Pacific, from Baja California to the Gulf of California, in shallow intertidal areas. The species also extends north, to California in the United States.
Habitat: Shallow waters and intertidal zone, in shelters, usually down to 10 m.
rules for the bay blenny
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.
Poses no danger to anglers. It is a small fish: release it quickly, without keeping it out of the water for long.
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.00871, b = 3.0; 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: Hypsoblennius gentilis (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Hypsoblennius gentilisNames 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: