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FishBrackishMarineIntermediate

Singapore Mono

Monodactylus kottelati

An elegant, diamond-shaped silver fish that forms tight schools in coastal waters. Juveniles adapt to freshwater, but adults thrive in spacious 250L brackish aquariums with a robust omnivorous diet.

Taxonomy

Class:Actinopteri

Order:Perciformes

Family:Monodactylidae

Genus:Monodactylus

Species:Monodactylus kottelati

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Water Temperature

24 - 28 °C

pH Value

7.5 - 8.5

Water type

Brackish / Marine

Tank level

Middle

Adult size

12 cm

Minimum tank volume

>= 250 L

Minimum group

>= 6

Species description

Geographical Origin and Habitat:

This species is native to the eastern Indian Ocean, including the coasts of India, Sri Lanka, and Singapore. It inhabits shallow coastal waters, estuaries, bays, and mangrove swamps, moving between freshwater, brackish, and marine environments.

Taxonomy and Morphology:

Member of the Monodactylidae family. It features a highly laterally compressed, diamond-shaped body. In aquariums, it grows to a maximum height and length of about 12 cm. The dorsal and anal fins are tall and scale-covered, forming a triangle.

Social Behavior:

An active, peaceful, and tightly schooling fish. It must be kept in groups of at least 5 to 6 individuals to prevent shyness. They establish a mild social hierarchy and swim dynamically in the mid-to-upper water levels.

Coloration and Sexual Dimorphism:

Body is bright silver with a metallic sheen. It has two dark vertical bands on the head: one running through the eye and another across the operculum. The tips of the dorsal and anal fins are yellowish-green with black margins. No visible dimorphism.

Care, breeding and tankmates

Aquarium Setup:

Requires a spacious tank of at least 250 liters for a school. Provide plenty of open swimming area and decorate with driftwood to mimic mangrove roots. Aquatic plants are difficult to keep, as the fish will nibble on them and they cannot tolerate high salinity.

Diet and Feeding:

Voracious omnivore. Accepts high-quality flakes, floating pellets, and frozen foods like brine shrimp, mysis, and bloodworms. It is essential to provide vegetable matter such as spirulina flakes, nori sheets, or blanched spinach to ensure good health.

Water Quality:

While juveniles tolerate freshwater, adults must be transitioned to brackish or marine water to survive long-term. Maintain temperature at 24-28°C, pH at 7.5-8.5, and salinity between SG 1.005 and 1.015 using marine salt. High-flow filtration is recommended.

Compatibility and Cohabitation:

Peaceful and suitable for community tanks with brackish species of similar size, such as archerfish, scats, and other monos. Avoid keeping them with very small or slow-moving fish, which may be stressed during the school's high-speed feeding frenzies.

Aquarium Breeding:

No successful breeding cases have been documented in home aquariums. In nature, they are protandrous hermaphrodites that migrate to seawater reefs to release pelagic eggs, a complex life cycle that has not been replicated in captivity.

Risks and Diseases:

Highly sensitive to poor water conditions. Keeping them in freshwater indefinitely will lead to fin rot, fungal infections, and faded colors. Maintain high oxygen levels and perform regular water changes to prevent stress and disease.

Geographic Origin and Distribution

Origin

Tropical oceans and reefsSouth and Southeast Asia

Fish profile

Temperament: Aggressive
Diet: Omnivore
Sex ratio: School
Feeding frequency: TWO_THREE_DAILY
Bioload: The bioload for this active fish is quite significant. They consume large amounts of food constantly. A robust biological and mechanical filtration setup is necessary.
Flow: Strong
Jump risk: No
Reproduction: Protandrous hermaphrodite
Compatibility & tankmates: Verify
Tank level: Middle

FishBase

Window to the official scientific data of the species

Data synced on: 06/15/2026

Scientific Parameters & Models

Trophic level: 3.3 ± 0.4 se
Phylogenetic uniqueness (PD50): 0.625
Bayesian Length-Weight: a = 0.02399, b = 3.01

Image gallery

Licensed images linked to the species or, when marked, to the closest representative taxon.

Related species

Recommendations grouped by close relatives, companion choices, and similar care.

Variants and close relatives

Same atlas type, nearby scientific identity, genus, or family.

African Mono

Monodactylus sebae

Species description

Care, breeding and tankmates