Paludarium Fish Stocking Options Guide: Goby Killifish Ricefish

The water section of a paludarium is shallow, often 15-25cm deep, with limited swimming volume and gentle waterfall flow. Paludarium fish stocking demands species that suit those constraints — surface-dwelling, low-flow, calm-tempered fish that handle warm tropical conditions without elaborate filtration. This guide from Gensou Aquascaping at 5 Everton Park covers the species that consistently work in Singapore paludarium builds, with attention to bioload, behaviour and the way paludarium fish stocking integrates with amphibian or invertebrate cohabitation.

Peacock Gudgeon

Tateurndina ocellicauda is the prototypical paludarium fish — colourful, peaceful, and small at 5-7cm. Native to Papua New Guinea streams, peacock gudgeons swim mid-water in calm flow and accept the shallow paludarium volume happily. Pairs bond strongly and breed in cave shelters, making them ideal community centrepieces. Singapore shops carry them at SGD 8-12 each. Stock 4-6 in a 60cm paludarium for visible activity without overcrowding.

Sparkling Gourami

Trichopsis pumila is the dwarf gourami of the paludarium world — 3-4cm, peaceful, with iridescent blue-green flecks across a brown body. They breathe atmospheric air through a labyrinth organ, so shallow water with surface access suits them perfectly. Males click audibly during display. Stock 4-6 in groups; pairs spawn in bubble nests under floating leaves. SGD 4-6 each at most local shops.

Clown Killifish

Epiplatys annulatus is a top-dweller specialist that almost evolved for paludariums. The orange and black banded body floats just below the surface waiting for fallen insects. Shallow water with overhead cover from emergent plants is the natural habitat. Pairs spawn in floating moss. Stock 6-10 in a 60cm build. SGD 8-15 each — slightly pricier than community fish because most Singapore stock is wild-caught West African.

Ricefish (Medaka)

Oryzias latipes and related species like O. woworae handle paludarium conditions effortlessly. The Japanese medaka tolerates 18-30°C, the daisy ricefish brings sapphire-blue body colour, and both species school loosely at the surface. Ideal stocking density is 8-15 fish in a 60cm build. Singapore shops trade common medaka at SGD 3-5; daisy ricefish at SGD 8-15.

Celestial Pearl Danio

Celestichthys margaritatus (formerly Danio margaritatus) suits paludarium use because of size — under 2cm — and shoaling behaviour at all water depths. The black body with iridescent pearl spots and red fins reads brilliantly against dark substrate. Stock 10-20 in a 60cm build for proper shoaling display. SGD 4-8 each. Browse the small fish food range for micro pellets that match their tiny mouths.

Licorice Gourami

For specialist keepers, Parosphromenus species offer one of the most rewarding paludarium fish stocking choices. The deep red and blue colouration and intricate fin display behaviour reward patient observation. They demand soft acidic water, blackwater conditions, and dense leaf litter — all conditions a paludarium creates naturally. Stock single pairs only in 60cm builds. SGD 25-60 per pair from specialist breeders on Carousell.

Stocking Density and Bioload Maths

Paludarium water sections are small. Apply a stricter rule than full aquariums — 1cm of fish per 2 litres of water rather than the standard 1cm per litre. A 30 litre water section comfortably holds 10-15 small fish total. Overstocking shows fast: surface gasping during peak feeding, ammonia trace readings, and accelerated algae bloom. Run the water test kit weekly during the first month of stocking.

Cohabitation with Amphibians

Mixing fish with amphibians is generally discouraged because of disease transfer risk, but paludariums sometimes warrant it. Fire-bellied toads coexist with adult guppies and ricefish if the water section is large enough that the toads cannot easily catch them. Dart frogs do not enter water, so any paludarium fish are safe. Avoid fish in newt or salamander setups — both species are slow enough that even small fish nip at their gills.

Sourcing and Quarantine

Iwarna at the Aquariums of Singapore complex carries most paludarium-suitable species at competitive prices. C328 in Clementi handles the budget end. Carousell breeders trade rare killifish and ricefish at premium pricing. Quarantine all new fish in a separate 5-10 litre container with a sponge filter for 14 days before introducing to the paludarium — the bioactive substrate makes treatment of disease almost impossible after introduction. Pair stocking with quality aquascaping nets and tools for non-stressful transfers.

Related Reading

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• First Paludarium Build Decision Singapore Guide
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• Biotope Mangrove Estuary Paludarium Design Guide