Aquarist Atlas
Oddballs & Brackish · Brackish fish · Monodactylus

Monodactylus argenteus

(Linnaeus, 1758)

Silver moony, Silver mono, Diamondfish

Full synonymy (2)
  • Chaetodon argenteus Bloch & Schneider 1801 · junior synonym
  • Scomber rhombeus Forsskål 1775 · junior synonym

Source: Eschmeyer's Catalog of Fishes (Fricke, Eschmeyer & Van der Laan, eds.), California Academy of Sciences.

3 cited sourcesName checked against Eschmeyer’s Catalog of Fishes, update of

IUCNLEAST CONCERN · 2016
CARESNOT LISTED
Type localityIndiaper Catalog of Fishes
Scientific size10.5 in27 cm standard length
Temperature75–82 °F24–28 °C
Depth—not recorded
DietNot documented in the sources available to the atlas
BreedingNot documented for this species
Sexual dimorphismNot documentedNot documented for this species
PhotographsSee photosGoogle Images →

Monodactylus argenteus, the silver moony, is a schooling brackish-water fish of the Indo-West Pacific, described by Linnaeus in 1758. FishBase gives a maximum of 10.5 in SL and a temperature range of 24 to 28 degrees C, and the IUCN lists it as Least Concern.

What's in the name

Monodactylus
  • monosGreek — single
  • daktylosGreek — finger
argenteus
  • argenteusLatin — silvery

Taxonomy & naming

Linnaeus described the species in 1758, and the Catalog of Fishes gives the type locality simply as India. It belongs to Monodactylidae, the moonyfishes or monos, and the epithet is Latin for silvery.

Morphology

A tall, disc-shaped, silvery fish. FishBase gives a maximum of 10.5 in SL for males or unsexed fish.

Habitat

FishBase gives a temperature range of 24 to 28 degrees C. The species lives in estuaries, mangroves and coastal waters, and the young often move into fresh water. FishBase has no detailed habitat or distribution text for this entry in the atlas cache.

Feeding

Diet is not documented in the sources available to the atlas.

Mating

Courtship has not been described in the sources available to the atlas.

Breeding

Breeding in captivity has not been documented in the sources available to the atlas.

In the aquarium

Sold by one partner store, and FishBase lists it among fishes traded commercially. Moonies are kept in groups, and adults do better in brackish water than in pure fresh water. FishBase gives a temperature range of 24 to 28 degrees C and no pH or hardness range.

Conservation

The IUCN Red List classes Monodactylus argenteus as Least Concern, assessed in June 2016.

Common questions

Silver moony (Monodactylus argenteus): how big does it get?
Up to 10.5 in standard length (SL).
Silver moony (Monodactylus argenteus): what water temperature does it need?
The atlas records 75–82 °F for this species.
Silver moony (Monodactylus argenteus): where does it come from?
It is recorded from India.

Also from the Indo-West Pacific

Sources

  1. FishBase — Monodactylus argenteus (Linnaeus, 1758)
  2. Eschmeyer's Catalog of Fishes (California Academy of Sciences) — Monodactylus argenteus
  3. IUCN Red List — Monodactylus argenteus

Naming authority: Monodactylus argenteus in Eschmeyer’s Catalog of Fishes ↗

Last reviewed 2026-10-05.

How to cite

Aquarist Atlas (2026). Monodactylus argenteus. Aquarist Atlas.https://www.aquaristatlas.com/oddballs/monodactylus-argenteus/

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Where it has been recorded

80 georeferenced records (GBIF). Each point is a field observation or museum specimen — pan and zoom to explore where this species turns up. The coordinates come straight from GBIF and are often rounded or tied to the nearest town or river landing, so a dot can sit just beside the actual water rather than in it.

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