scythemarked butterflyfish
Prognathodes falcifer
Solitary butterflyfish of reefs and rocky areas in the eastern Pacific, from 10 to 150 m deep. It rarely reaches aquariums, because it lives in deeper water.
Also called: borboleta-de-foice, mariposa guadaña, scythemarked butterflyfish
- maximum
- 15 cm
- depth
- 10–150 m
who is the scythemarked butterflyfish
Butterflyfish of the family Chaetodontidae, with a tall, disk-shaped, compressed body. It reaches 15 cm. It lives on rock areas and reef boulders of the eastern Pacific, from southern California to Peru, including the Galápagos, from 10 to 150 m. It is usually solitary and forms pairs during breeding. It feeds on crustaceans, worms and small invertebrates. It has commercial use, but since it lives in deeper water it is seldom collected and rarely seen in 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 scythemarked butterflyfish; in the meantime, see the similar species.
fun facts
- Close relatives pull the tube feet off sea urchins and eat them.
identification
Tall, compressed, disk-shaped body, with a short, deep profile, like all butterflyfish. The common name, sicklefin butterflyfish, refers to a sickle-shaped mark on the body. The habitat helps tell it apart: this species lives from 10 to 150 m, in areas with boulders, and is usually seen alone, deeper than other eastern Pacific butterflyfish, such as the blacksnout butterflyfish (Johnrandallia nigrirostris).
Loading the next 7 days…
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.
Essential profile: the index uses a general fish model (weather, sun, moon and tide), without a season or time of day specific to this species.
where found
Eastern Pacific of Latin America, in Mexico and Ecuador, including the Galápagos, in rocky areas from 10 to 150 m.
Habitat: Areas with boulders and rocks on reefs, from 10 to 150 m deep.
rules for the scythemarked butterflyfish
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 danger to anglers has been recorded. It is a small fish of deep waters: handle it with a wet hand and return it to the water carefully.
how much it weighs without taking it out of the water
Length-weight relationship W = a·Lb (a = 0.02239, b = 3.01; FishBase (relação peso-comprimento bayesiana, estimativa)). 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: Prognathodes falcifer (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
- scientific FishBase: nomes populares de Prognathodes falciferNames by country and language.
