Characidae, Hemigrammus Clade Common Names:
Rummynose Tetra, Brilliant Rummynose Tetra Origin and Habitat:
Basins of the Rio Meta and Rio Negro in Columbia and Brazil, and the Atabapo in Venezuela. Occurs in quiet blackwater streams and flooded forest; often sympatric with Paracheirodon axelrodi (cardinal tetra). Compatibility/Temperament:
Very peaceful shoaling tetra, must be in a group of at least six but this species is definitely better with larger numbers, and 12 or more will make quite a difference. Well suited to a well planted community aquarium of non-aggressive fish such as other characins, dwarf cichlids, and small barbs, rasbora, anabantids, catfish and loaches. Very suitable for discus. Brilliant Rummy Nose Tetra Diet
Omnivorous, it accepts prepared foods including flake and frozen. Size
Attains 2 inches, usually smaller. Minimum Tank Suggestion
24 inches in length can suffice, but this species should have at least a 30-inch tank and will be better with 36 inches and up. Water parameters for Brilliant Rummy Nose Tetra
Soft (hardness not exceeding 12 dGH but preferably below 5 dGH) and acidic (pH below 7.0, preferably below 6.5) water, temperature 23-26C/74-79F. Tolerates warmer temperatures to 29C/84F. Habitat waters are very soft with a pH from 3.7 to 5. Description
There are three distinct species, Hemigrammus rhodostomus, H. bleheri
and Petitella georgiae
, under the common name "Rummy Nose Tetra" and H. bleheri
is certainly the most colourful and is now the most commonly available of the three. This species is easily distinguished from the other two; only in this species does the red colour extend beyond the head onto and past the gill covers. Also, the central caudal fin band extending laterally onto the body of the fish that is quite evident in the two similar species is almost non-existent in H. bleheri
. The chart included below illustrates the three species.The red colouration is brightest in this species, though this can be misleading as it pales if the fish is under stress and it usually would be in dealer's bare tanks. The "original" Rummynose, H. rhodostomus, is unlikely to be encountered today; P. georgiae is sometimes available [see that profile]and when combined with the subject species, they will all remain together.
While most of the characins are shoaling fish, this tetra is the one that almost always remains within a group. It swims in the lower third of the aquarium, normally surfacing only to feed. Swimming space is essential, as the species likes to regularly venture out from among the plants as a group to swim the full length of the aquarium.
This fish will take on its brightest colouration in a well-planted aquarium with a dark substrate and slightly acidic and soft water, and shaded by floating plants since it does not appreciate bright lighting.
Females are rounder than males, but this species is not easy to spawn and this will only be successful in very soft acidic water. The eggs are scattered in fine leaf vegetation to which they adhere, and will be eaten by the adults if not removed. Eggs and fry are very sensitive to light, another indicator of the dark waters in which this fish occurs.
The brilliant red colouration will only appear when the fish is comfortable with its environment, and any paling of the red is an indicator of stress, often due to deteriorating or unsuitable water conditions.
This species was the last of the three "Rummynose" tetras to be discovered, and this occurred in 1965 by Heiko Bleher; the species was described and named in honour of its discoverer by Gery and Mahnert in 1986.
The genus Hemigrammus
--the name derived from the Greek hemi
(=half) and grammus
(= line) 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). References:
Bleher, Heiko (2010), "Rummynose Tetras," Practical Fishkeeping
7 (July 2010), pp. 18-21.
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