Longspine Cardinal (Pristiapogon kallopterus)

The Longspine Cardinalfish (Pristiapogon kallopterus) is a peaceful, reef-safe nano schooling fish with a silvery body, a dark lateral stripe through the eye, and the namesake long first dorsal-fin spine. Cardinals are mouth-brooders and crepuscular, so they tend to drift quietly under overhangs by day and come out to hunt small prey at dawn and dusk. Pair them with our other saltwater fish in a calm community reef.

Longspines look their best in small groups of three to five — they school loosely above the rockwork and bring movement to the mid-water column without ever bullying tank mates.

Care Guide

• Tank size: 30 gallons minimum for one, 55+ for a group of three to five.
• Diet: Carnivore. Frozen mysis, brine, fine pellets, and live copepods. They eat small bites and prefer slow-sinking foods.
• Feeding frequency: Twice daily. Soak frozen food in a vitamin enhancer to keep colors strong.
• Temperament: Peaceful. Will not pester other fish or invertebrates.
• Reef safe: Yes with all corals, clams, and invertebrates. Adult cleaner shrimp and hermits are safe; very tiny ornamental shrimp may be picked.
• Acclimation: Slow drip 45 minutes. Cardinals can be shy on arrival; dim lights and offer a piece of frozen food the next day.

Specifications

Tank Mates & Compatibility

Pairs well with most peaceful reef community species: clownfish, royal grammas, firefish, small wrasses, blennies, gobies, and tangs. Avoid notably aggressive tank mates such as dottybacks, large damsels, triggers, and groupers that will out-compete a quiet cardinal at feeding time.

Excellent reef tank citizen — ignores corals, clams, snails, and shrimp. A group of three to five is the most natural and visually striking arrangement.

Recommended Foods & Supplies

• SFBB Freeze-Dried Mysis — small enough for the Cardinal's modest bite.
• BRS Premium Saltwater Pellets — slow-sink pellet that drifts past their hunting zone.
• Reef Nutrition Tigger Feast — live copepods to seed the rockwork.
• Bulldawg Live Brine Shrimp Nauplii — fresh live food encourages newly arrived cardinals to start eating.
• Salt mixes — keep parameters stable with a quality synthetic salt.

FAQ

Can I keep just one?
Yes, but a small group of three to five is far more natural and they school together attractively. Single cardinals tend to hide more.

Will it eat my pods?
Yes, light copepod grazing is normal. Run a refugium if you have a mandarin or pipefish in the same system.

Why does it hover under the rockwork all day?
Cardinals are crepuscular — most active at dawn and dusk. Daytime resting under overhangs is normal, not a health concern. They come out at feeding time.

Will it breed in the tank?
Many cardinals will pair up and the male mouth-broods the eggs for one to two weeks. Survival of fry in a reef tank is rare, but witnessing the brooding is a treat.