The Fraser's danio (Danio fraseri) is a species of small freshwater fish belonging to the family Cyprinidae, which includes carps and minnows. It is native to Southeast Asia and is known for its characteristic slender body and distinctive markings.
Taxonomy and Etymology
- Scientific Name: Danio fraseri
- Family: Cyprinidae
- Order: Cypriniformes
- Class: Actinopterygii (Ray-finned fishes)
- The species epithet fraseri likely honors a collector or individual associated with its discovery or study.
Description
Fraser's danio is a relatively small fish, typically reaching an adult length of about 3 to 4 centimeters (1.2 to 1.6 inches). Its body is elongated and streamlined, characteristic of many danio species. The base coloration ranges from a silvery-gold to an olive hue, often with iridescent qualities. It features distinct longitudinal patterns along its flanks, which can vary in appearance from broken stripes to rows of spots, usually darker, metallic blue, or blackish. The fins are generally translucent or may have a subtle yellowish tint. Like other Danio species, it possesses a pair of small barbels near its mouth.
Habitat and Distribution
This species is endemic to specific regions of Myanmar (formerly Burma) in Southeast Asia. It is primarily found in the Irrawaddy River basin and its associated tributaries. Fraser's danio typically inhabits clear, fast-flowing hill streams and smaller rivers. These environments often feature rocky or gravel substrates, moderate to dense aquatic vegetation, and well-oxygenated water.
Diet
Fraser's danio is an omnivorous species. In its natural habitat, its diet primarily consists of small invertebrates, such as insect larvae and small crustaceans, as well as zooplankton. It may also supplement its diet with some algal matter.
Behavior and Reproduction
Fraser's danio is a schooling fish, preferring to live in groups. This social behavior provides a sense of security and is typical for many small cyprinids, reducing individual predation risk. They are generally peaceful fish.
Reproduction in Danio fraseri follows the typical egg-scattering strategy of many cyprinids. Spawning involves the broadcast of eggs over the substrate, and there is no parental care once the eggs are laid.
Conservation Status
The conservation status of Danio fraseri has not been widely assessed by major international organizations such as the IUCN. Like many localized freshwater fish species, it may be susceptible to threats such as habitat degradation, water pollution, and overcollection for the aquarium trade, especially in areas experiencing rapid environmental changes.
Aquarium Keeping
Fraser's danio is occasionally kept in the aquarium hobby, though it is less common than some other Danio species like the zebra danio. When kept in aquariums, it requires:
- Water Parameters: Clean, well-oxygenated water with good filtration.
- Tank Setup: A planted tank with open swimming spaces is ideal. Substrates of gravel or sand mimic its natural environment.
- Temperament: It is a peaceful community fish, suitable for tanks with other small, non-aggressive species.
- Temperature: Optimal water temperature typically ranges from 20-26°C (68-79°F).
- Diet in Captivity: Readily accepts a varied diet of high-quality flake foods, small pellets, and frozen or live foods such as brine shrimp, daphnia, and bloodworms.