About the Emerald Dwarf Rasbora
Species Type: Freshwater Fish
Care Level: Moderate. May tolerate only a narrow range of water parameters, have specific dietary requirements including frozen or even live foods, may have behaviors that severely limit potential tankmates or may require a specialized aquarium setup.
Origin: SE Asia: Lake Inle basin in Shan state, eastern Myanmar. Inhabits the weedy shallows at the edges of the lake, among thick vegetation.
Compatibility/Temperament: Peaceful and shy; males are territorial and will nip each other's fins; must be in a group of at least six, but in a well-planted 15 or 20 gallon tank a larger group (15-20) may reduce this somewhat. Best suited to a species tank; may manage in a community of similar small, non-aggressive fishes that will not out-compete them for food and that share the cooler temperature and slightly basic water.
A beautiful and very small fish that deserves its own tank. A 10 gallon tank will suffice for a group of 6-8, but the males' feistiness will be less damaging to each other in larger groups in more spacious tanks. The aquarium should have a dark substrate and be very heavily planted, and include floating plants. Pay attention to the specific water parameters or this fish will waste away. Regular water changes are also essential. The water in its habitat is very clean and crystal clear.
The males are more colourful and slightly smaller than the females. With nutritious foods (live or frozen) spawning will likely occur. This species is an egg scatterer; parents should be removed after spawning as they will readily devour the eggs.
When originally described by N. Annandale in 1918, this species was placed in the genus Microrasbora. Roberts (2007) questioned the genus, and that same year Mayden et.al. determined that the species then in Microrasbora are in fact phylogenetically closer to Danio than Rasbora, and subsequently all but one of the species were moved to other genera; Microrasbora rubescens is the sole confirmed species in the genus, although M. microphthalma and M. rubescens "Thuzari" are still uncertain. Conway et.al (2008) moved the subject species into Danio, and subsequent authorities such as Fang, Kullander and others have confirmed this placement. It is likely that these beautiful fish may appear under either name for some time.
Conway, K.W., W.-J. Chen and R.L. Mayden (2008), "The 'Celestial Pearl danio' is a miniature Danio (s.s.) (Ostariophysi: Cyprinidae): evidence from morphology and molecules," Zootaxa, No. 1686, pp. 1-28.
Mayden, R. L., K. L. Tang, K. W. Conway, J. Freyhof, S. Chamberlain, M. Haskins, L. Schneider, M. Sudkamp, R. M. Wood, M. Agnew, A. Bufalino, Z. Sulaiman, M. Miya, K. Saitoh, S. He, (2007), "Phylogenetic relationships of Danio within the order Cypriniformes: a framework for comparative and evolutionary studies of a model species," Journal of Experimental Zoology, Part B, Molecular and Developmental Evolution, 308(5), pp. 642-654.
Roberts, T.R. (2007), "The 'Celestial Pearl Danio,' a new genus and species of colourful minute cyprinid fish from Myanmar (Pisces: Cypriniformes)," The Raffles Bulletin of Zoology, volume 55 (no. 1), pp. 131-140.
Emerald Dwarf Rasbora Diet
Prefers live foods such as brine shrimp, microworms, daphnia, and insect larvae, but can be acclimated to prepared foods such as frozen brine shrimp, bloodworms, daphnia; may accept flakes.
Attains 2 cm (.75 inch) maximum.
Minimum Tank Suggestion
10 gallons for a group of 6.
Ideal water parameters for Emerald Dwarf Rasbora
Slightly soft to medium hard (hardness 10-20 dGH), slightly basic (pH 7-7.6), temperature 20-24C/68-75F. These ranges replicate the habitat, and available fish will be wild-caught. This is one rasbora that does not fare well in acidic water.