Yellowstriped Cardinalfish (Ostorhinchus cyanosoma)
The Yellowstriped Cardinalfish (Ostorhinchus cyanosoma), known to tropical fish keeping enthusiasts as the Yellow-striped Cardinalfish, Orange-lined Cardinalfish, Goldenstriped Cardinalfish, and Gold-line Cardinalfish, is native to the tropical Indo-West Pacific Ocean.
Its vast range extends from the Red Sea and the Persian Gulf southward to Mozambique, stretching across the Indian Ocean east to Fiji, north to the Ryukyu and Bonin Islands of Japan, and south to Fiji, New Caledonia, and Tonga.
Yellowstriped Cardinalfish are a peaceful, slow moving species that typically inhabit the sheltered, clear-water lagoons and seaward coral reefs of their range at depths ranging from 3 to over 165 feet where they gather in small to large aggregations inside caves, under ledges, or safely tucked among the long spines of Diadema sea urchins.
Yellowstriped Cardinalfish are carnivorous nocturnal planktivores that during the day gather into tight, highly organized schools or small aggregations. They spend the day hovering completely motionless deep inside dark caves, rock crevices, or under shaded reef ledges. They often use the sharp spines of Diadema sea urchins or branching corals to shield themselves from predators.
At night the schools leave their daytime shelters and break apart into individuals or loose pairs to scour the reef flats and sandy microhabitats for zooplankton, benthic copepods, tiny shrimp and micro crustaceans.
Yellowstriped Cardinalfish (Ostorhinchus cyanosoma)
The Yellowstriped Cardinalfish has a sleek, elongated semi translucent silver body color with striking, neon bluish iridescent undertones, decorated with six vibrant horizontal stripes that can be golden yellow to deep orange. The stripes run from the snout across the large, dark, golden ringed eyes, all the way back to the base of the caudal fin. Their mostly transparent fins have a faint yellow to orange tint, and they have two separate dorsal fins.
Yellowstriped Cardinalfish (Ostorhinchus cyanosoma) are frequently confused with the Southern Orange-lined Cardinalfish (Ostorhinchus properuptus) which share a nearly identical long, slender body shape. The main differences between the two are the number of horizontal stripes, how the lowermost stripe travels along the body, and their geographic range.
Yellowstriped Cardinalfish (Ostorhinchus cyanosoma)
Interestingly, their physical appearance subtly shifts at night under the cover of darkness; the distinctive midlateral orange spot near the base of the tail turns a vivid, deep red.
The Yellowstriped Cardinalfish can be housed in a mature FOWLR or reef aquarium of at least 20 gallon capacity for a single specimen or pair, with a coralline sand or gravel substrate and plenty of mature live rock arranged into deep caves, dark overhangs, and wide crevices for them to shelter in during the day.
In a reef tank, adding a Diadema sea urchin will replicate their natural habitat.
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 Yellowstriped Cardinalfish is best housed in small schools of 5 to 7 invididuals in a larger 30 to 55 gallon aquarium.
Because they are so peaceful and slow moving, they can be safely housed with other small, passive, docile species. Ideal tankmates include related species like Banggai (Pterapogon kauderni) and Pajama Cardinalfish (Sphaeramia nematoptera); small bottom dwellers like Neon Gobies, Clown Gobies, Firefish, Tailspot Blennies, and Midas Blennies; and passive open water swimmers like Royal Grammas, Orchid Dottybacks (if added last), and small, peaceful wrasses like the Possum Wrasse or Flasher Wrasses.
The Yellowstriped Cardinalfish is completely reef safe. They will not bother corals or ornamental clams but large specimens in theory will eat tiny, newly hatched ornamental shrimp and small worms in the system. They are absolutely safe with larger ornamental Cleaner Shrimp, Fire Shrimp, crabs, snails, and all types of soft or stony corals.
Breeding Ostorhinchus cyanosoma in a home aquarium environment is entirely possible, but it presents a much higher difficulty level than breeding the popular Banggai Cardinalfish. Although they readily spawn in captivity, rearing their tiny, pelagic larvae make them a true challenge for advanced aquarists.
Like other members of the Apogonidae family, Yellowstriped Cardinalfish are paternal mouthbrooders. They form distinct pairs and after a brief courtship and spawing, the female produces a sticky cluster of approximately 150 to 300 demersal, adhesive, 0.3 to 0.7 mm eggs that the male incubates in his mouth for approximately 7 – 10 days until the larvae are ready to be released, during which time the male does not feed. The tiny fry are normally releaed at night into the water column with no further parental care.
Rearing the microscopic larvae requires a dedicated separate tank with gentle flow and live micro-copepod cultures.
In their natural environment, Yellowstriped Cardinalfish feed almost entirely on meat based micro-organisms like reef shrimp, amphipods, sergestid crustaceans, floating zooplankton, copepods, fish larvae, small worms, microscopic snails, and organic scraps that drift past the reef.
In an aquarium environment, they should be fed enriched brine shrimp, Mysis shrimp, Calanus, Cyclops, finely chopped fresh shrimp, scallops, clams, and protein rich micro pellets or crushed omnivore flakes.
Feed them once at dawn as the tank lights turn on and at dusk right after the LEDs turn off and the blue moonlight is on. Feeding gut loaded brine shrimp or live copepods at night will immediately trigger their natural hunting instincts.
The Yellowstriped Cardinalfish (Ostorhinchus cyanosoma) is widely available to tropical fish keeping enthusiasts from a variety of local fish shops and online retailers at prices ranging from $16 to $35 or more depending on size, area of collection, and if they are captive bred specimens.
Yellowstriped Cardinalfish (Ostorhinchus cyanosoma)
Minimum Tank Size: 20-30 gallons
Aquarium Type: FOWLR or Reef
Temperament: Highly Peaceful
Aquarium Hardiness: Very Hardy
Water Conditions: 72-78° F, dKH 8–12°, pH 8.1-8.4, sg 1.020-1.025
Max size: 2.5″
Color Form: Silver, Neon Blue, Orange, Yellow
Compatibility: Reef Safe
Origin: Indo-West Pacific Ocean, Red Sea, Fiji, Tonga
Family: Apogonidae
Lifespan: 5-7 years
Aquarist Experience Level: Beginner
