Threadfin cardinalfish
The threadfin cardinalfish is a small, translucent-bodied planktivore widespread across Indo-Pacific reefs and lagoons, where it hovers in tight aggregations among branching Acropora corals by day. Its semi-transparent, silvery body shows fine iridescent markings and delicate elongated dorsal rays. Peaceful and rather shy, it should be kept in a shoal of at least eight in a mature reef aquarium of 150 litres or more, ideally with plenty of coral or rock structure for shelter. Provide stable reef conditions: temperature 24 to 27 C, salinity 33 to 35 ppt, pH 8.1 to 8.4 and moderate carbonate hardness. Feed frequent small portions of enriched brine and mysis shrimp, copepods and quality frozen zooplankton, as this micropredator has a fast metabolism. Reef-safe and undemanding once acclimated, it appreciates gentle flow and subdued lighting near cover.
Water parameters
| Temperature | 24 – 27 °C |
|---|---|
| pH | 8.1 – 8.4 |
| Carbonate hardness (KH) | 8 – 12 °dKH |
| Salinity | 33 – 35 SG |
Tank & stocking
| Minimum tank volume | 150 L |
|---|---|
| Volume budget per individual | 30 L — adds up with tank-mates |
| Minimum group size | 8 individuals (shoaling) |
“Minimum tank volume” is a reasonable floor, not an absolute limit. The per-individual budget is used by the Aqua app to estimate how heavily a tank is stocked.
Frequently asked questions
What size aquarium does Threadfin cardinalfish need?
Provide at least 150 litres for a small group to keep Threadfin cardinalfish in good conditions.
What water parameters does Threadfin cardinalfish need?
A temperature of 24–27 °C, pH 8.1–8.4, saltwater.
Is Threadfin cardinalfish peaceful or aggressive?
Its temperament is peaceful.
What does Threadfin cardinalfish eat?
Its diet: planktivore.
How many Threadfin cardinalfish should be kept together?
It is a social species: keep a group of at least 8.
How big does Threadfin cardinalfish get?
Around 6 cm as an adult.
Is Threadfin cardinalfish suitable for beginners?
Care level: intermediate.
Planning a tank with Threadfin cardinalfish?
AquaTender turns these parameters into live advice: it checks whether your tank is big enough, how heavily it's stocked, and whether your fish are compatible — then tracks water tests, photos and maintenance for you.
Fish from the same biotope
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