We're considering two different though related species here. The fish linked by Evanleigh is
Badis badis. The
Dario dario is what comes up as "gem" for me and others it seems. Here are some excerpts from profiles I wrote a couple years back that may be of help. I have kept the smaller Dario dario, and would agree they may not eat dry or prepared foods.
Badis badis
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Family: Badidae
Common Names: Badis, Chameleon Fish
Origin and Habitat: Ganges River system (India, Nepal, Bangladesh), Mahanadi River drainage (India), Assam lowlands (India); Buthan and Pakistan. There is some differentiation in colouring depending upon the locale. Found in solitude along the margins of slow-moving rivers and streams with thick vegetation, and in ponds, ditches and swamps.
Compatibility/Temperament: Peaceful in a community tank of non-active and non-aggressive fish that prefer the slightly cooler temperatures; it may not eat if kept with active feeders. It will naturally prey upon shrimp. Should not be combined with similar lower level fish such as dwarf cichlids as these will be seen as rivals. Males are territorial and can be aggressive so a pair (male/female) should be housed in a 24-inch tank and a group requires larger aquaria.
Badis Diet
Feeds naturally on worms, crustaceans and insects. They are shy deliberate feeders [see under Description] that at least initially may require live foods such as worms, artemia, daphnia; frozen bloodworms, daphnia and brine shrimp should be accepted, and some fish may eventually accept dried foods.
Size
Males attain slightly over 3 inches (8 cm) but usually around 2.4 inches (6 cm) in aquaria, with females slightly smaller.
Minimum Tank Suggestion
24 inches in length for a pair.
Water parameters for Badis
Soft to medium (< 15 dGH), slightly acidic to slightly basic (pH 6 to 7.5) water. Habitat waters are subject to considerable seasonal temperature variation, but in the aquarium 20-25C/68-77F is recommended. Spawning will require warmer water at the upper end of this range.
Dario dario
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Family: Badidae
Common Names: Scarlet Badis
Origin and Habitat: Brahmaputra River system in Assam and northwest Bengal states, India. Found in shallow streams thick with aquatic or marginal vegetation and a sand or gravel substrate.
Compatibility/Temperament: A naturally shy and retiring fish, it may be maintained in a community tank of very peaceful fishes that are not active such as smaller rasbora (Boraras and Trigonostigma sp.), pygmy gourami, small characins, and any of the dwarf Corydoras species. Males may be aggressive particularly in small tanks.
Scarlet Badis Diet
Naturally feed on insect larvae, small crustaceans, worms, zooplankton; offer live foods (artemia, blackworms, daphnia), frozen bloodworms, daphnia and brine shrimp. Active tankmates may result in this fish refusing to eat.
Size
Males attain 2 cm, females less; the smallest known percoid species.
Minimum Tank Suggestion
5 gallons but preferably 10 gallons.
Water parameters for Scarlet Badis
Soft to medium hard (< 15 dGH), acidic to basic (pH 6 to 8) water, temperature 18-26C/65-79F.