roughear scad
Decapterus tabl · Carangidae · forage fish
Small schooling fish of the shelf, with a red tail, often used as bait.
Also called: xaréu-rabo-vermelho, caballeta rabicolorá, roughear scad
- maximum
- 50 cm
- record/max.
- 0.6 kg
- depth
- 150–220 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…
—
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 roughear scad
who is the roughear scad
The red-tail jack belongs to the family Carangidae and reaches 50 cm. It lives on the shelf, usually between 150 and 220 m, in midwater or near the bottom, and also rises to the surface. It feeds mainly on copepods and other small plankton invertebrates. It is sold fresh and is often used as bait. It occurs from the North American Atlantic to Venezuela, and also in Brazil and Argentina. It has been recorded down to 550 m, but is most common between 150 and 220 m.
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 roughear scad; in the meantime, see the similar species.
fun facts
- The maximum recorded depth is 550 m.
identification
Fusiform body, metallic blue to greenish on the back and silvery below. It has a small black spot on the edge of the gill cover, a bright red tail, and the tips of the soft dorsal fins tinged red. The last rays of the dorsal and anal fins are set apart from the rest, forming small finlets. To tell it from the garaçuma (Trachurus lathami), look at the red tail and these finlets.
where found
It occurs from the North American Atlantic to Venezuela, and also in Brazil and Argentina, in shelf waters.
Habitat: Continental shelf, in midwater or near the bottom, usually between 150 and 220 m.
coast
rules for the roughear scad
Summary of the regulations we found, with the source for each. Rules change; before keeping or transporting fish, check with the state environmental agency.
Conservation: Not on the Brazilian national list (Ministerial Ordinance GM/MMA No. 1.667/2026).
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 danger to anglers. As it comes from bottoms of 150 m or more, it suffers barotrauma on the way up; release it carefully and quickly.
in the kitchen
Sold fresh; also used as bait.
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.0123, b = 3.01; 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
—
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: Decapterus tabl (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Decapterus tablNames by country and language.
- official Portaria GM/MMA nº 1.667, de 27 de abril de 2026: Lista Nacional Oficial de Espécies da Fauna Ameaçadas de Extinção (peixes e invertebrados aquáticos)The species is not on the list. Checked in the DOU of April 28, 2026.
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: