Clade Common Name:
Penguin Tetra Origin and Habitat:
Middle (central) Amazon basin, middle Tocantins basin and Rio Guapore basin, South America. Streams in dense forested areas. Compatibility/Temperament:
A peaceful shoaling fish compatible with similarly peaceful fish like characins, rasbora, danio, gourami, angelfish, dwarf cichlids, small catfish and loaches. Penguin Tetra Diet
They are particularly carnivorous. They will appreciate live foods. Insects falling on the water surface are likely consumed by this fish. Feed frozen foods such as daphnia and bloodworms; should accept prepared foods. Size
Grows to 3.2 inches. Minimum Tank Suggestion
30 inches in length. Water parameters for Penguin Tetra
Soft (hardness to 15 dGH) acidic (pH below 7.0) water, temperature 22-28C/72-82F. Description
Penguin tetras are one of the characins with a very unique feature compared to other tetras; they can swim at a 45 degree angle due to low buoyancy of their tails. In the wild, these fish lie just below the surface among dense vegetation and feed on insects falling on the surface. In both these traits they closely resemble 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.
Up until about 1960 the related species Thayeria boehikei was shown in the literature under the common name of Penguin Tetra and that species is the more common in the hobby. It has a separate Profile.
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