Spotted Cardinal

Spotted Cardinalfish (Sphaeramia nematoptera)

Overview

The Spotted Cardinalfish (Sphaeramia nematoptera), also known as the Threadfin Cardinalfish, is a small, peaceful marine fish native to the Indo-Pacific region, including Indonesia, the Philippines, and northern Australia. It is recognized by its silver body, translucent fins, and distinct black spots along its sides.

This species is social, often forming small groups or pairs, and is an excellent addition to community or reef aquariums due to its calm temperament and attractive appearance.

Aquarium Requirements

• Minimum Tank Size: 30 gallons (115 litres)

• Temperature: 24–27°C (75–81°F)

• pH: 8.1–8.4

• Specific Gravity (Salinity): 1.020–1.025

• Alkalinity: 8–12 dKH

• Ammonia & Nitrite: 0 ppm

• Nitrate: < 10 ppm

• Aquascape: Provide ample hiding places with live rock, caves, or coral overhangs, along with open swimming areas

Spotted Cardinalfish thrive in established aquariums with stable water parameters and sheltered areas for retreat.

Diet and Feeding

Spotted Cardinalfish are carnivorous and require a protein-rich diet:

• Frozen foods such as mysis shrimp, brine shrimp, and finely chopped seafood

• High-quality marine pellets or flakes formulated for carnivorous species

• Feed small portions 2–3 times daily, preferably in the evening

Frequent feeding ensures optimal health, coloration, and energy levels.

Temperament and Compatibility

This species is peaceful and suitable for small community or reef tanks. They may be kept in small groups or pairs and generally coexist well with other non-aggressive species.

Tankmate Recommendations:

• Suitable: Gobies, blennies, firefish, small anthias, and other peaceful reef fish

• Avoid: Large, aggressive, or predatory species

Providing secure hiding spaces encourages natural schooling and reduces stress.

Reef Compatibility

✅ Reef Safe

Spotted Cardinalfish are reef safe and do not harm corals, invertebrates, or sessile organisms, making them ideal for reef aquariums.

Additional Information

• Maximum Size: Up to 10 cm (4 inches)

• Lifespan: 5–7 years with proper care

• Difficulty Level: Easy to Moderate

• Natural Behavior: Peaceful, social, often forms small groups, active mostly at dusk and night

• Origin: Indo-Pacific, including Indonesia, the Philippines, and northern Australia

The Spotted Cardinalfish (Sphaeramia nematoptera) is a small, peaceful, and visually appealing marine fish that adds color, activity, and social behavior to community and reef aquariums. With stable water conditions, a protein-rich diet, and ample hiding places, it thrives as a long-lived and engaging member of the aquarium community.