About the Purple Tetra
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: Rio Orinoco basin, especially the tributary Rio Meta, Columbia. Inhabits sluggish rivers and streams.
Compatibility/Temperament: Very peaceful and somewhat timid, it must be maintained as a group (minimum six) and does very well in aquaria with similar peaceful fish such as many of the characins (hatchetfish and pencilfish are ideal, tetras such as the cardinal, green neon, ember, etc), small catfish, discus, or dwarf cichlids. It will not do well with boisterous or very active tankmates.
Unfortunately rare in the hobby, this precious fish will always be wild-caught and deserves the attention it demands in terms of water parameters and environment; it should only be introduced to a well-established and stable aquarium. In bright or sparse aquaria it will be pale and stressed and remain hidden and rarely venture out; but maintained in a group of at least six in a thickly-planted aquarium with a dark substrate and lighting subdued by floating plants, it will be out and about, occupying the middle level. With its larger size, purple and black flanks, bright red eye, and lateral stripe ending in the upper and lower shining spots on the caudal peduncle, it is a good contrast companion for very small fish such as Hyphessobrycon amandae (Ember Tetra) and pencilfish.
Females are slightly heavier in appearance than males; there are no other external sexual characteristics. Spawning in typical characin fashion will occur if the fish are maintained as suggested.
The fish bears something of a resemblance to H. herbertaxelrodi (Black Neon Tetra) but is more colourful and deeper bodied. It was described as H. metae [the species epithet is derived from the Rio Meta from which the type specimens were collected] by Eigenmann & Henn in 1914, but is often confused in the literature with H. peruvianus, and somewhat less so with H. loretoensis (Loreto Tetra). Gery (1984) suggested that these three may actually be conspecific with local forms or subspecies. Hyphessobrycon and Hemigrammus are "catch-all" genera for more than 200 known species, and many will undoubtedly be reclassified by ichthyologists after intensive research and study.
The genus Hyphessobrycon--the name from the Greek "hyphesson" [believed to mean "slightly smaller"] and "brycon" [=to bite]--was erected by C.H. Durbin in 1908 and presently contains more than 100 valid species. The classification is deemed incertae sedis [Latin, "of uncertain placement"]. It was formerly considered within the Subfamily Tetragonopterinae, but Javonillo et.al. (2010) suggest that this subfamily should be restricted to species within the genus Tetragonopterus since they do not share physiological characteristics with species in other genera such as Hyphessobrycon.
Authors that have recently studied the systematics of the genus Hyphessobrycon have unanimously pointed out that the group is not well defined and its monophyly is yet uncertain. [A monophyletic genus is one wherein the species share a common ancestor, thus linking them together physiologically.] Mirande (2009) for example has 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. The recognition of groups of species [clades] within Hyphessobrycon is based primarily on similarities of color patterns; an hypothesis of its intra-relationships is currently unavailable, except for the rosy tetra clade proposed as monophyletic by Weitzman & Palmer (1997).
Hyphessobrycon has until recently been differentiated from Hemigrammus solely on the basis of the fish in Hemigrammus possessing a scaled caudal fin; this however is now known to be unreliable, since it occurs in intermediate conditions (de Lucina, 2003).
de Lucena, Carlos Alberto Santos (2003), "A new characid fish, Hyphessobrycon scutulatus, from the Rio Teles Pires drainage, upper Rio Tapajos system (Ostariophysi: Characiformes: Characidae)," Neotropical Ichthyology 1 (2), pp. 93-96.
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).
Weitzman, Stanley H. & Lisa Palmer (1997), "A new species of Hyphessobrycon (Teleostei: Characidae) from the Neblina region of Venezuela and Brazil, with comments on the putative 'rosy tetra clade'," Ichthyological Exploration of Freshwaters volume 7 (no. 3), pp. 209-242.
Purple Tetra Diet
Feeds on invertebrates naturally, will accept most prepared foods like flake, frozen daphnia and bloodworms; live brine shrimp and worms are a treat.
Maximum 2 inches.
Minimum Tank Suggestion
36 inches in length.
Ideal water parameters for Purple Tetra
Soft (hardness below 8 dGH) acidic (pH below 6.5) water, temperature 22-28C/72-82F. It will not thrive in basic (alkaline) conditions.