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catalog Chaetodontidae · omnivore

bank butterflyfish

Prognathodes aya

Butterflyfish of deep banks in the Gulf of Mexico, down to Yucatán, between 45 and 170 m. It is hardly seen even by divers and rarely reaches the line.

Also called: borboleta-de-banco, mariposa de banco, bank butterflyfish

Scientific illustration of Bank butterflyfish
maximum
15 cm
depth
45–170 m
overview

who is the bank butterflyfish

Butterflyfish of the family Chaetodontidae, with a tall, compressed body, living on deep open-sea reefs, between 45 and 170 m. It reaches 15 cm. It occurs from North Carolina and the northeastern Gulf of Mexico to Yucatán, Mexico, and is not known from the Bahamas or the Antilles. Because it lives deep, divers hardly see it. It pairs up for breeding and lays eggs in the water. It has commercial value for the aquarium trade, but is rarely fished.

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 bank butterflyfish; in the meantime, see the similar species.

fun facts

  • It lives on deep reefs where divers rarely see it.
how to recognize it

identification

Tall, compressed body, with a wide dark band sloping backward from the middle of the spiny dorsal fin to the base of the rear part of the anal fin. Unlike the shallow-water butterflyfishes of the region, such as Chaetodon ocellatus, this one lives on deep reefs, from 45 to 170 m, and the dark band is the main mark.

how bank butterflyfish fishing looks

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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.

distribution

where found

open on the large map

In Latin America it is known only from Mexico, from the Gulf of Mexico to Yucatán. Its presence in the Bahamas and the Antilles is not known.

Habitat: Deep open-sea reefs, 45 to 170 m.

what the law says

rules for the bank 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.

It poses no danger to the angler. Since it comes from great depth, it suffers barotrauma if it rises quickly, so release it as deep as possible.

calculator

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

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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.

  1. scientific FishBase: Prognathodes aya (ficha da espécie)Size, length-weight, depth, habitat, distribution, biology, and IUCN status. Page checked on Oct 13, 2026.
  2. scientific FishBase: nomes populares de Prognathodes ayaNames by country and language.
don't confuse

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