Blackfin Cardinalfish (Astrapogon puncticulatus)
The Blackfin Cardinalfish (Astrapogon puncticulatus) known to tropical fish keeping enthusiasts as the Narrowlined Cardinalfish and Punctate Cardinalfish is native to the Western Atlantic Ocean.
Its range extends from Bermuda and Southeast Florida, the Bahamas, and across the Caribbean Sea and Gulf of Mexico; and southward along the coast of South America to Brazil.
The Blackfin Cardinalfish is a cryptic, shallow-water dwelling species that during daylight hours are found alone or in pairs hovering motionless within dark shelters, shallow reef flats, lagoons, and tidepools at depths from 0 to over 25 feet, though they have been recorded as deep as 187 feet.
During the day in the shallower inshore environments where they are most commonly encountered in depths from 2 to 15 feet, Blackfin Cardinalfish are often found nestling within dense, clear seagrass beds (Thalassia testudinum) or sheltering inside empty gastropod shells, such as discarded snail or conch shells.
Although Blackfin Cardinalfish will occasionally hover over soft sandy or muddy bottoms near the base of a reef structure, they will rarely venture out over open sand flats devoid of overhead cover or protective benthic debris.
Blackfin Cardinalfish are strictly nocturnal predators that are fiercely territorial of their individual shelters by day and merge into loose, temporary aggregations to forage in the open water on small benthic and pelagic crustaceans, zooplankton, and tiny fishes at night.
When a Blackfin Cardinalfish hunts in the dark, it utilizes its large eyes to detect microscopic movements of prey. Unlike some related species that interact with bioluminescent ostracods, it relies entirely on its exceptional night vision to ambush tiny copepods and shrimp moving through the seagrass canopy.
Blackfin Cardinalfish (Astrapogon puncticulatus)
The Blackfin Cardinalfish has a bronze, pale brown, or tan colored body with mottled lines, dark blotches, and a fine peppering of black dots; a large, oblique, extendable mouth, and oversize eyes with a dark pupil, a bright reflective bronze-yellow iris, and four dark bars radiating outward from the center.
They have two separate dorsal fins that feature a heavily blackish front tip on the first dorsal fin, large jet-black or dark grey pelvic fins, and a rear edge on the second dorsal, anal, and tail fins that remains distinctly clear or translucent.
Males have a larger, broader squared-off jawline to accommodate brooding, and retain a leaner, more compressed body profile than females which are noticeingly plumper.
The Blackfin Cardinalfish (Astrapogon puncticulatus) is often confused with the Conchfish (Astrapogon stellatus), which is a closely related but distinctly different Western Atlantic species that lives inside the mantle cavity of living queen conchs, whereas the Blackfin Cardinalfish will only inhabit empty shells.
The Blackfin Cardinalfish can be housed in a mature FOWLR or reef aquarium of at least 30 gallon capacity with an aragonite sand or bare bottom substrate, plenty of live rock stacked into dark shaded caverns, and empty conch or large snail shells scattered along the floor for them to shelter among. Because they startle easily, a tight fitting mesh or glass lid is mandatory, and a programmable LED with Moonlight setting is recommended to provide subdued lighting and keep them from staying hidden. An oversized protein skimmer, strong filtration system and a small power head is recommended to maintain water quality and provide low to moderate movement.
The Blackfin Cardinalfish are reef safe with caution. They will not touch corals or ornamental clams but large specimens will
opportunistically eat tiny ornamental shrimp and small worms.
Unless you are buiying a guaranteed, pre-bonded mated pair, only place one Blackfin Cardinalfish per tank. Putting two random Blackfin Cardinals in a 30 gallon tank will result in severe territorial fighting over preferred hiding shells.
In larger FOWLR or reef tanks Blackfin Cardinals can be housed with peaceful, non aggressive species that occupy different levels in the tank such as Royal Grammas, Firefish Gobies, Clownfish or Tailspot Blennies.
Avoid aggressive predators like Groupers, Lionfish, Eels, Frogfish, large Hawkfish and Wrasses and hyperactive fish like Maroon Clownfish, Dottybacks, large Tangs, Damselfish and large aggressive Angelfish.
The Blackfin Cardinalfish is exceptionally rare in the aquarium environment and successfully raising the fry to adulthood is difficult.
Unlike Banggai Cardinalfish which release fully formed, large miniature juveniles that can immediately eat baby brine shrimp, Blackfin Cardinals release tiny, microscopic pelagic larvae that require a dedicated, separate rearing tank equipped only with a very gentle air stone and constant access to specialized, live microscopic copepod cultures.
Blackfin Cardinalfish are paternal mouthbrooders that after a brief courtship carry out spawning. A pair will produce a sticky, cohesive, ball-like mass consisting of thousands of extremely small eggs. The male catches the fertilized egg mass in his mouth where he aerates them by churning them and rolling them around. After fasting during the incubation period, the tiny fry are released at night into the plankton rich ocean currents to feed on microscopic copepod nauplii until they become juveniles and eventually adults.
A mature female Blackfin Cardinalfish (Astrapogon puncticulatus) typically produces a clutch of several hundred to over a thousand eggs per spawning cycle.
In the wild, Blackfin Cardinalfish are nocturnal ambush predators that feed on zooplankton, mysid shrimp, copepods, amphipods, and small fish fry. In an aquarium environment they should be initially fed live or frozen mysis shrimp, enriched brine shrimp, calanus, and finely chopped seafoods at dusk or dawn. Feed adults 1 or 2 times a day, juveniles 2 to 3 times a day, and post brooding males at least 2 to 3 times a day. Feeding once in the morning and once in the evening replicates their nocturnal schedule.
The Blackfin Cardinalfish (Astrapogon puncticulatus) is rarely available to tropical fish keeping enthusiasts and is seldom seen at online retailers, wholesalers, or local fish shops, but when available, prices generally range from $20.00 to $55.00 depending on size, supplier, and area of collection.
Because they are not captive bred on a commercial scale and lead a highly secretive lifestyle, the marine aquarium trade relies entirely on accidental or rare wild-caught imports from the Caribbean. They are usually only available by special request.
Blackfin Cardinalfish (Astrapogon puncticulatus)
Minimum Tank Size: Single specimen 30 gallons
Aquarium Type: FOWLR or Reef
Care Level: Moderate (due to shyness and feeding requirements)
Temperament: Semi-Aggressive
Aquarium Hardiness: Hardy
Water Conditions: 72-78° F, dKH 8 – 12°, pH 8.1-8.4, sg 1.020-1.025
Max size: 2.0”
Color Form: Bronze, Brown, Tan, Black [0]
Diet: Carnivore [0]
Compatibility: Reef Safe with Caution
Origin: South Florida, Bahamas, Caribbean, Bermuda, Brazil
Family: Apogonidae
Lifespan: 3-5 years
Aquarist Experience Level: Intermediate/Advanced
