Pajama Cardinal (Sphaeramia nematoptera)
Pajama Cardinal (Sphaeramia nematoptera) known to tropical fish keeping enthusiasts as Sphaeramia nematoptera, Spotted Cardinalfish, or Red Spotted Cardinalfish is found in the western Pacific Ocean and Indo-Australian Archipelago.
Their range in the Western Pacific extends from the Ryukyu Isslands in southern Japan down to the Great Barrier Reef in Australia; in Oceana and Indo-Malayan the span eastward from Java and Indonesia all the way to Fiji; and in Micronesia they are common throught Palau, Truk, and the Caroline Islands.
The Pajama Cardinal is a peaceful, largely nocturnal species that is most commonly found in small to large schools in the shallow, sheltered coastal reefs, lagoons, and mangrove estuaries of their range at depths from 3 to 50 feet where they hover near branching Porites or Acropora corals, caves, or sea urchins during the daylight hours.
Sphaeramia nematoptera are a nocturnal benthic feeding species that shelter in the crevices of live rock, among the branches of Porites corals or between the long spines of longspine sea urchins during the day and disperse at night as solitary hunters to feed on small crustaceans like shrimp, crabs, mysids, and amphipods; zooplankton like isopods, copepods and free floating crustacean larvae; and small microscopic marine worms and tiny gastropods. Their large, light-sensitive eyes allow them to spot tiny, translucent prey in pitch black water.
Pajama Cardinal (Sphaeramia nematoptera)
The body of the Pajama Cardinal has a greenish yellow colored front half, divided by a bold, black vertical band in the middle of their body, followed by an orange to brown spotted polka dot posterior half that is a cream to off white color. They have large, bright orange to red colored eyes and elongated forked fins.
The Pajama Cardinal is best housed in groups of 5 or more individuals in a mature FOWLR or reef aquarium of at least 55 gallon capacity with a sandy or fine coralline gravel substrate, plenty of live or dry rock arranged into deep caves, overhangs and archways, with moderate water flow, and plenty of free swimming space.
They are completely reef safe and will shelter among Porites or Acropora corals, Hammer corals, Torch corals, or plating Montipora as well as Long spined sea urchins (Diadema) that they share a symbiotic relationship with.
Pajama Cardinals are a peaceful, shy species that can be housed in a FOWLR tank with other peaceful, slow moving reef species. Suitable tank mates include; Possum Wrasse, Streaked Wrasse, Ocellaris or Percula Clownfish, Royal Gramma (Gramma loreto), Dottybacks (e.g., Orchid Dottyback), Ruby Red Dragonet, Firefish (Nemateleotris spp.), Cleaner Shrimp (Lysmata amboinensis), Blue Green Chromis, or Hawkfish (e.g., Flame Hawkfish).
Avoid Damselfish, Dottybacks, Six Line Wrasses, large Tangs, groupers, snappers, hawkfish, and Lionfish.
Pajama Cardinals are paternal mouthbrooders that have been bred in an aquarium environment however rearing the larvae remains extremely challenging.
In the wild, Pajama Cardinals form long term social pairs. The male takes full responsibility for incubating the fertilized eggs inside his mouth until they hatch out as undeveloped, microscopic larvae.
Courtship typically takes place during the twilight hours. Pairs separate themselves from the school and swim in tight circles, side by side, flicking or twitching their bodies until they finally align parallel to each other as they spawn. The female releases an adhesive egg mass that contains dozens of tiny eggs that the male immediately fertilizes externally and gathers up into his mouth. Once the eggs are in his mouth he becomes passive and vulnerable.
The female then takes over to aggressively guard the brooding male from any harm. The male churns the egg mass inside his bulbous distended mouth to oxygenate and aerate the enbryos until they hatch out in 7 to 8 days as microscopic larvae. Males frequently hold the larvae for up to 2 weeks before releasing them into the water column. After initially spawning, a pair will reliably spawn every 2 to 3 weeks.
In their natural habitat, Pajama Cardinals are nocturnal planktivores and micro-carnivores that feed on planktonic crustaceans, benthic crustaceans, invertebrate larvae and very small, newly hatched fish.
In an aquarium environment they are easily acclimated to accept a wide variety of foods like frozen Mysis shrimp, vitamin enriched brine shrimp, chopped krill, calanus, and cyclops; live blackworms, adult brine shrimp, copepods, amphipods, and once acclimated high quality marine flakes and small micro-pellets.
Pajama Cardinals are slow, deliberate swimmers with small mouths that cannot compete with aggressive tankmates for food. They require 2 to 3 small daily feedings with one as the reef lights are cut off.
The Pajama Cardinal (Sphaeramia nematoptera) is widely available to tropical fish keeping enthusiasts from a variety of online retailers, wholesalers, and local fish shops at prices that range from $13.99 to $49.99 depending on size, area of collection and if they are wild caught or captive bred.
Pajama Cardinal (Sphaeramia nematoptera)
Minimum Tank Size: Single specimen 20 gallons, 55 gallons for small schools
Aquarium Type: FOWLR or Reef
Care Level: Easy
Temperament: Peaceful
Aquarium Hardiness: Hardy
Water Conditions: 74-80° F, dKH 8 – 12°, pH 8.0-8.4, sg 1.020-1.025
Max size: 4”
Color Form: Greenish Yellow, Black, Light Tan, Red Orange
Diet: Carnivore
Compatibility: Reef Safe
Origin: western Pacific Ocean
Family: Apogonidae
Lifespan: 5 – 8 years
Aquarist Experience Level: Beginner
