Clade Common Name:
Pristella Tetra, X-Ray Tetra Origin and Habitat:
South America: basins of the Amazon and Orinoco, and coastal river drainages of the Guianas. Found in calm coastal waters and in densely vegetated swamps inland. Compatibility/Temperament:
Very peaceful and somewhat active, a good community fish with other characins, small catfish and loaches, dwarf cichlids, the hardier gourami species, angelfish, rasbora, barbs or livebearers. Pristella Tetra Diet
Omnivorous, will accept practically any prepared flake, dry or frozen food. An active feeder. Size
Reaches 1.75 inches when mature. Minimum Tank Suggestion
A tank 24 inches in length. Water parameters for Pristella Tetra
Very adaptable for a tetra. Soft to slightly hard (hardness to 30/35 dGH), acidic to basic (pH up to 8.0) water, temperature 24-28C/74-82F. In hard water it will not be colourful. Description
Due to its adaptability to varying water conditions and being quite hardy, this tetra is a good fish for almost any community aquarium and well suited to new aquarists. Shoaling by nature, it must be kept in a group of at least six but preferably more. It does not appreciate bright lighting, and although adaptable to basic harder water, it will not achieve maximum colouration in hard water. This is one of the few characins that occur in brackish water in the coastal habitat of its range, though aquarium fish are commercially raised and best suited to freshwater without salt. In a well-planted aquarium with soft water it will sparkle.
No external sexual dimorphism; females are noticeably stockier than males. A prolific spawner in soft, acidic water; in its habitat, it moves into the flooded savannah and spawns among the thick vegetation where the water is soft and acidic due to the dissolved organic matter.
This species was described by Ulrey in 1894, and is currently the only species in the genus; the older name Pristella riddlei
is incorrect and now considered a synonym. Gery grouped this genus with Megalamphodus
(Black and Red Phantoms), noting that it was very close to the Hyphessobrycon bentosi
group. [Weitzman & Palmer (1977) reassigned the Megalamphodus
species to Hyphessobrycon
.] Aside from internal similarities, these species share a "signal" black spot on the dorsal that is usually framed by white. Gery (1977) surmised that the species enter into protective associations with each other.
The genus Pristella
was previously considered within the subfamily Tetragonopterinae, but this classificationhas for some time been deemed incertae sedis
[Latin for "of uncertain placement"]. Javonillo, et al. (2010) determined that the subfamily Tetragonopterinae should only be used for species within the genus Tetragonopterus
. Also, J. Marcos Mirande (2009) proposed several revisions to the family Characidae based upon phylogenetic diagnosis. Some genera have been moved to a new subfamily, while others are now (temporarily) assigned to a specific clade within the family pending further study. References:
Javonillo, Robert, Luiz R. Malabarba, Stanley H. Weitzman and John R. Burns (2010), "Relationships among major lineages of characid fishes (Teleostei: Ostariophysi: Characiformes), based on molecular sequence data," Molecular Phylogenetics and Evolution
, Vol. 54, No. 2 (February 2010).
Mirande, J. Marcos (2009), "Weighted parsimony phylogeny of the family Characidae (Teleostei: Characiformes)," Cladistics
, Vol. 25, No. 6 (July 2009). Contributing Members
The following members have contributed to this profile: Byron