Characidae, Hemigrammus Clade Common Names:
Pretty Tetra, Ornate Tetra, Garnet Tetra, Black Wedge Tetra Origin and Habitat:
South America: Upper Amazon basin in Peru, in slow moving streams under forest cover. Compatibility/Temperament:
Very peaceful and somewhat active tetra, well suited to a community tank of most characins, small catfish and loaches, rasbora, danios, angelfish, dwarf cichlids and gourami. Must be kept in a group, minimum 6 but preferably more. Pretty Tetra Diet
Primarily carnivorous in nature, it will readily accept most prepared foods including flake and frozen. Size
Attains 2 inches. Minimum Tank Suggestion
24-30 inches in length Water parameters for Pretty Tetra
Soft (hardness to 12 dGH) and slightly acidic (pH below 7.0) water, temperature 23-27C/73-81F. Description
This species is one of several in the Hemigrammus ocellifer
group, species that have one or two humeral spots and one spot on the caudal peduncle (tail base). In this species, the caudal spot glows like copper-toned phosphorus, larger and more colourful than the closely-related and similar Head and Tail Light Tetra and there is a distinctive black wedge below the spot. There are two humeral spots, one also copper-coloured. The fish has a violet or coppery-toned sheen over the body that in certain angles under the light sparkles and glistens. The iris of the eye is a brilliant red.
Colourful in a well-planted and dimly lit aquarium, in brighter light and spartan conditions the fish colour pales due to stress. The fish swims in the upper middle region of the aquarium, and there is a lot of interaction between members of the group. While six is the minimum, this species does better with eight or more.
The fish are ready spawners but spawning in the aquarium is not easy; it requires soft acidic water with dim light and plants in which the eggs are deposited. Males are more slender and have a pointed swim bladder which can be discerned through the somewhat transparent skin, while females have a rounded swim bladder and are thicker-bodied. When in spawning mode, the copper-red colour in the male's anal fin is much brighter than that of the female.
This species is sometimes seen under the additional common names of Garnet Tetra or Black Wedge Tetra. It is somewhat rare in the hobby, but well worth searching for; a truly sparkling gem compared to the more common Head and Tail Light Tetra. A similar bodied but less colourful fish considered a possible subspecies is now established as a distinct species, Hemigrammus haraldi
The genus Hemigrammus
--the name derived from the Greek and meaning "with half line," a reference to the incomplete lateral line--was erected as a subgenus of Poecilurichthys
by T.N. Gill in 1858 but has been recognized as a distinct genus since Gery (1977). There are presently about 50 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 Hemigrammus
None of the diagnostic characteristics presently used to describe species in Hemigrammus
, including the incomplete lateral line which gave rise to the genus name, are unique to the genus. Mirande (2009) states that the genus is not monophyletic, a view shared by most ichthyologists working with the characidae. [A monophyletic genus is one wherein the species share a common ancestor, thus linking them together physiologically.] Mirande 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. Hemigrammus
has until recently been differentiated from Hyphessobrycon
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.
Gery, Jacques (1977), Characoids of the World
, TFH Books.
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