Clade Common Names:
Penguin Tetra, False Penguin Tetra, Hockeystick Tetra Origin and Habitat:
Rio Araguaia in Brazil and the Peruvian Amazon. Compatibility/Temperament:
Peaceful, suitable for a community tank with other characins, rasbora, danio, gourami, angelfish, dwarf cichlids, small catfish and loaches (acid water) or livebearers (basic water). False Penguin Tetra Diet
A typical characin predator of insects, worms, etc., it will accept most prepared foods and appreciate frozen daphnia and bloodworms or live foods. Size
Grows to 2.4 inches, possibly up to 3 inches. Minimum Tank Suggestion
24 inches in length. Water parameters for False Penguin Tetra
Soft to moderately hard (hardness up to 20 dGH) acidic to slightly basic (pH up to 8.0) water, temperature 22-28C/72-82F. Description
Of the three species in the genus, this is the most popular and common in the hobby. This species was originally described in the literature as the Penguin Tetra, being confused with the true Penguin Tetra, T. obliqua
[see separate Profile], which confusion was resolved when Dr. Stanley Weitzman described and named the subject species in 1957. The photos accompanying the Profiles show the difference between the two species.
Like the other two species in the genus, this one also swims in a head-up position at 45 degrees; it also remains close to the surface among vegetation, preying on insects that fall onto the water. Both traits are shared with the two pencilfish species Nannostomus eques
and N. unifasciatus
Should be kept in a group of six or more in a well-planted aquarium. Tank should be covered as they may jump if given the opportunity. Unlike the other two species in the genus, this species can be maintained in slightly basic (alkaline) water aquaria.
The genus Thayeria
was previously considered within the subfamily Tetragonopterinae, but this classification has 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