Bank butterflyfish (Prognathodes aya)

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Chordata · Class: Teleostei · Order: Acanthuriformes · Family: Chaetodontidae · Genus: Prognathodes.

Accepted name: Prognathodes aya · Authority: (Jordan, 1886) · Taxonomic status: accepted · AphiaID: 273370.

Synonyms and superseded combinations recorded for this taxon: Chaetodon aya Jordan, 1886; Chaetodon eques Steindachner, 1903.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=273370 (CC BY 4.0). Accessed 2026-09-25.

Biology and life history (FishBase)

Measured values published by FishBase for Prognathodes aya. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.

Maximum length: 15 cm · Depth range: 20–170 m · Habitat zone: reef-associated · Body shape: short and / or deep · Vulnerability index: 10 of 100 · Fishery importance: commercial · Aquarium trade: commercial.

FishBase notes: Inhabit deep offshore reefs (Ref. 4858). Rarely seen by divers (Ref. 4858). Oviparous (Ref. 205). Form pairs during breeding (Ref. 205).

Source: FishBase species summary (SpecCode 3601) — https://www.fishbase.se/summary/Prognathodes-aya.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-25.

Distribution and occurrence records (GBIF)

2,498 georeferenced occurrence records for Prognathodes aya are published through GBIF from 7 countries or marine areas. The map above plots 70 distinct locations from a sample of 2,498 records, omitting 3 inland records that carry an institution's coordinates rather than a collection site; it shows where the species has been observed and reported, not a modelled range.

Most records by country or area: Puerto Rico (2,085); United States of America (391); Mexico (18); Guyana (1); India (1).

The full country table, WoRMS marine regions and the sampling notes are on this species' Distribution page.

Source: GBIF Occurrence Search (taxonKey 2385603) — https://www.gbif.org/occurrence/search?taxon_key=2385603&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=273370 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-25.

Conservation status (IUCN Red List)

The IUCN Red List assesses Prognathodes aya (Jordan, 1886) as Least Concern (code LC). No trend, population estimate or threat analysis is given here, because none is available from this source without the Red List API; follow the source link for the full assessment, including its date.

Source: IUCN Red List of Threatened Species (taxon 165621) — https://www.iucnredlist.org/species/165621/0; GBIF IUCN Red List category endpoint (taxonKey 2385603) — https://api.gbif.org/v1/species/2385603/iucnRedListCategory. Accessed 2026-09-25.

Description and natural history (Wikipedia)

The Bank butterflyfish is silvery white to tan in color, with yellow on all fins except the pectoral fins. It also has two sub-vertical dark, brownish, bars: the first lies across its eyes and follows the profile of the face and snout; the second begins at the back of the dorsal fin and extends downward near the tail but does not appear on the caudal fin. There is also a yellow band located behind the second dark bar that extends from the fifth spine of the dorsal fin, down to the back of the anal fin.

The Bank butterflyfish is uncommon throughout its range. It is found on natural and artificial reefs in Florida, the Gulf of Mexico, and off the Yucatán Peninsula. It is also found as far north as North Carolina, though it only rarely appears that far north.

In regard to conservation, the Bank butterflyfish is not known to be threatened in any way and is listed as Least Concern by the IUCN. Though it is harvested for use in salt water aquaria, this commercial use does not appear to negatively impact the global population of the species. The Bank butterflyfish is also not protected by name in any specific legislation, though it is known to inhabit a number of protected areas.

When observed by scuba divers this fish is generally regarded as shy, and it is known to dart into the shelter of reefs upon approach. Once properly sheltered, however, some fish will remain at the entrance to whatever crevice they are using, apparently to watch divers.

Source: Wikipedia: Bank butterflyfish — https://en.wikipedia.org/wiki/Bank_butterflyfish (CC BY-SA 4.0). Accessed 2026-09-25.