Long-Spine Cardinal Fish Duo

WYSIWYG - Approx. Size: 1.25 Inches

Introduction to Saltwater Cardinalfish

Cardinalfish are slow-moving, nocturnal reef fish known for their peaceful nature and striking appearances. Found in seagrass beds and coral reefs, they prefer to hover in groups near rock formations or branching corals for shelter. Their hardy nature and ease of care make them perfect for beginner and experienced aquarists alike. Unlike many schooling fish, cardinalfish do well in small groups or pairs and are one of the few saltwater species that can successfully breed in home aquariums.

Care Requirements

Care Level: Easy – Well-suited for beginner reef keepers Minimum Tank Size: 20+ gallons (for a small group, larger for more individuals) Aquarium Setup: Requires ample rockwork or branching corals for shelter Thrives in low to moderate flow Best kept in groups of 3 or more for natural behavior Cardinalfish are not active swimmers, preferring to hover near structures, making them a great choice for smaller reef tanks. Diet & Feeding Cardinalfish are carnivores that require a protein-rich diet to stay healthy. Diet Type: Carnivorous – Prefers small invertebrates and meaty foods

Recommended Foods:

Mysis shrimp and brine shrimp High-quality marine pellets and flakes Copepods, amphipods, and other small live foods Regular feedings of small, meaty foods help maintain vibrant coloration and overall health.

Lifespan & Growth Rate

Lifespan: 3-5 years Size Potential: Typically grows 2-4 inches, depending on the species Cardinalfish remain relatively small, making them an excellent choice for nano and medium-sized reef tanks.

Temperament & Compatibility

Temperament: Peaceful – Does well in community and reef tanks Reef Safe? Yes – Completely safe with corals and invertebrates Use Caution With: Large predatory fish like lionfish or groupers may view them as prey Keeping multiple cardinalfish together helps reduce stress and encourage natural behavior.

Common Challenges & Considerations

Nocturnal Behavior: Cardinalfish are most active at night and may appear shy during the day. Best Kept in Groups: While not true schooling fish, they feel more secure in small groups. Slow Eaters: They may be outcompeted for food by faster, more aggressive feeders. Providing a well-structured tank with hiding spots ensures they feel secure and display their best colors.

Color Varieties & Popular Species

Cardinalfish come in a variety of eye-catching colors and patterns, making them a stunning addition to reef aquariums. Popular Cardinalfish Species: Banggai Cardinalfish (Pterapogon kauderni) – Silver body with black bands and white spots, one of the few saltwater fish that breed in captivity Pajama Cardinalfish (Sphaeramia nematoptera) – Greenish-yellow head, black midsection band, and red-spotted tail Red Spot Cardinalfish (Apogon parvulus) – Small schooling species with a bright red body Flame Cardinalfish (Apogon spp.) – Striking orange-red coloration, peaceful and reef-safe