By Bob Goemans
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Prognathodes aculeatus

Poey, 1860

Caribbean Longnose Butterflyfish, Rosy Butterflyfish, Altantic Longnose Butterflyfish

Not Reef Tank Suitable

Likely Fish-Only Tank Suitable

Range: Western Atlantic Ocean: Southern Florida, Gulf of Mexico and the Caribbean to Venezuela.

Size: 4 inches (10 cm)

Natural Environment: Inhabits reef faces, fore-reef slopes and drop offs at depths from about 3 to 450 feet (1 – 135 m) and feeds on worms, crustaceans, feet of unchins, fish eggs, and black coral polyps. Occurs singly and is most abundant at 100 foot (30 m) depths.

General Husbandry: Quite attractive and hardy, as it has a whitish belly that becomes more yellowish towards the top of the body and while its dorsal fins are blackish, its pelvic and anal fins are yellow. There’s also a narrow tannish band over the head from eye to eye, which ends just prior to the eye.

Adapts quite easily to aquarium life in larger peaceful fish-only community aquariums, especially those with lots of open swimming space. A meaty diet of live fortified brine shrimp, black worms (Lumbriculus variegatus), and/or various frozen meaty foods such as mysis, should be offered several times daily.

Its recommended there be only one species from this genus in the aquarium, as they tend to develop aggression toward others of the same genus, yet not others in other family genera.

Not safe with LPS corals, gorgonians, snails, and tubeworms/feather dusters.

Rarely is there a problem getting this species to feed in the aquarium, however, small human consumption clams/black mussels purchased in local grocery stores and placed on the half-shell in the aquarium will help entice it to begin feeding. Over time, frozen foods like mysis and brine shrimp will be more readily accepted.


    Order: Perciformes

    Suborder: Percoidei

    Family: Chaetodontidae

    Genus: Prognathodes

FYI: Those in this genus are usually referred to as ‘Longnose Butterflyfish.’

Pressing some soft foods into openings/crevices on a piece of old dead coral skeleton can sometimes encourage finicky eaters to begin feeding.

Experience Level: Intermediate

Temperament: Peaceful

Diet: Canivore

Coral Safe: No

Invertebrate Safe: No

Acclimation Time: 30 minutes+

Aquarium Environment: Fish-only aquarium

Tankmates: Peaceful or non-aggressive

Minimum Tank Size: 75 gallons

Temperature Range: 72 - 82°F (22 – 27°C)

Specific Gravity: 1.020-1.026

pH: 8.0 - 8.5

 Prognathodes aculeatus (Caribbean Longnose Butterflyfish, Rosy Butterflyfish, Altantic Longnose Butterflyfish)
Photo © Bob Fenner
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