Pajama Cardinalfish - Sphaeramia nematoptera

 

The Pajama Cardinalfish (Sphaeramia nematoptera) is a small, peaceful, and striking species of cardinalfish popular in reef aquariums. Known for its distinct appearance, it is easily recognizable due to its unique coloration and pattern, which resembles a pair of pajamas—hence its name.

Description:

• Common Name: Pajama Cardinalfish, Nightfish

• Scientific Name: Sphaeramia nematoptera

• Family: Apogonidae

• Size: Typically grows to about 3 inches (7.5 cm) in length.

• Coloration: The Pajama Cardinalfish has a striking coloration with a translucent body adorned with a vertical red or brown band, and reddish-brown spots on the rear half, which give it the appearance of wearing pajamas. It has a large, expressive eye, a characteristic feature of cardinalfish.

• Lifespan: With proper care, it can live for 5-7 years in a well-maintained aquarium.

Native Region:

The Pajama Cardinalfish is native to the Indo-Pacific region, including areas such as Indonesia, the Philippines, and parts of Australia. It inhabits reefs, lagoons, and coral-rich environments in shallow waters, typically between 5 to 30 meters (16-100 feet) in depth.

Aquarium Setup:

• Tank Size: A minimum of 30 gallons (114 liters) is recommended for a group of Pajama Cardinalfish. However, a larger tank is ideal, especially if you plan to keep multiple individuals to encourage natural schooling behavior.

• Aquascaping: Provide a tank with plenty of rockwork for hiding spots, as this species enjoys resting in crevices or under rocks. A sandy substrate is also preferred to mimic its natural environment.

• Water Flow: Moderate water flow is suitable. Avoid strong currents, as these fish are not particularly strong swimmers.

Water Parameters:

• Temperature: 72-78°F (22-26°C)

• pH: 8.1-8.4

• Salinity: 1.020-1.025 specific gravity

• Alkalinity: 8-12 dKH

• Nitrate: Below 10 ppm

• Phosphate: Below 0.03 ppm

Care Level:

• Difficulty: Easy to moderate. The Pajama Cardinalfish is generally hardy and adaptable, making it suitable for both beginner and experienced aquarists. However, it does best in well-established tanks with stable water conditions.

• Diet: The Pajama Cardinalfish is a carnivore and feeds on a variety of foods, including small live foods, frozen mysis shrimp, brine shrimp, and high-quality pellet food. It will readily accept frozen foods and live copepods, so providing a variety of food types will ensure it remains healthy.

• Behavior: Pajama Cardinalfish are peaceful and can be kept with a variety of other species in a community tank. They tend to swim in the middle to upper areas of the tank and can be quite active at night, hence their alternate name, “Nightfish.” They are also schooling fish, and it is best to keep them in groups to reduce stress and encourage natural behavior.

• Activity Level: Moderate. Pajama Cardinalfish are nocturnal to some extent, becoming more active during dusk and nighttime. During the day, they tend to rest in sheltered areas, usually in the rockwork or between corals.

Reef Compatibility:

• Reef-Safe: Yes, Pajama Cardinalfish are reef-safe. They are not aggressive toward corals or invertebrates and are generally peaceful with other fish.

• Tank Mates: Suitable for community aquariums with other peaceful species. They are compatible with other small fish such as gobies, blennies, and wrasses. As schooling fish, it is ideal to keep them in groups of 3 or more. Avoid keeping them with overly aggressive species, as they might become stressed.

• Avoid: Avoid keeping with very large or predatory fish, as they may view the Pajama Cardinalfish as prey.

Tank Maintenance:

• Feeding: Pajama Cardinalfish require a diet high in protein, such as frozen mysis shrimp, brine shrimp, copepods, or high-quality frozen foods. They may also accept pellets and flakes, but it is important to ensure that the fish is getting enough protein-rich food to thrive.

• Water Quality: Regular water changes and good filtration are crucial to maintaining a healthy environment for the Pajama Cardinalfish. They do not tolerate poor water quality, and frequent water changes will help maintain stable water parameters.

Additional Tips:

• Schooling Behavior: While the Pajama Cardinalfish is a peaceful species, it thrives best when kept in groups of at least three individuals. Keeping a small school encourages natural behavior and reduces the chances of stress-related issues.

• Acclimation: Proper acclimation is essential when introducing the Pajama Cardinalfish to a new tank. Use a drip acclimation process to gradually introduce the fish to the tank’s water parameters, ensuring it adjusts to the new environment without excessive stress.

• Hiding Spots: Provide plenty of crevices, caves, and rock structures where the fish can hide. Pajama Cardinalfish are naturally inclined to seek refuge during the day and will feel safer if they have access to these areas.