Apogon leptacanthus – Glass Cardinalfish

The Apogon leptacanthus, commonly known as the Filament-finned Cardinalfish, is a small, elegant reef fish, prized for its gregarious behavior and delicate appearance.

It is characterized by:

A silvery, thin, and translucent body

Thin, elongated dorsal filaments

Subtle yellow to golden reflections

Large, bright eyes, typical of cardinals

Native to the Indo-Pacific region, this species lives in lagoons and on sheltered reef slopes, where it forms scattered schools among branching corals and rocky crevices.

In an aquarium, it creates magnificent movements in open water when kept in a group.

Behavior in a reef aquarium:

✔ Peaceful and safe for the reef

✔ Best kept in groups (5 or more individuals recommended)

✔ Open water swimmer

✔ Generally non-aggressive

He feels safer and adopts natural behavior when kept in a group.

Care requirements

Minimum aquarium size: 208 litres (larger for groups)

Temperature: 24–26 °C
Density: 1.023–1.025
pH: 8.0–8.4
Layout: Living stones with caves and shaded areas

A mature and stable ecosystem is recommended.

Food
Carnivorous plankton feeder:

Mysis shrimp

Enriched Artemia

Finely chopped seafood

High-quality marine granules
Feed in small portions 2 to 3 times a day.

Compatibility
✔ Compatible with reef corals
✔ Compatible with invertebrates
✔ Compatible with other peaceful fish in a community aquarium

⚠ Avoid large, aggressive predators

Special notes
Sensitive to poor water quality

It can hide at the beginning

More active at dusk

Mouthbrooding (males incubate the eggs)