Scientists have described a new species of the tetra genus Hasemania.
Publishing their description in the latest issue of the journal Copeia, Vinicius Bertaco and Luiz Malabarba of Pontificia Universidade Catolica do Rio Grande do Sul have named the new species Hasemania nambiquara.
Hasemania nambiquara is only known from the Rio Doze de Outubro, a tributary of the Rio Juruena in the upper reaches of the Rio Tapajos, Comodoro, Mato Grosso, Brazil, the same locality where two species of Hyphessobrycon, H. melanostichos and H. notidanos, were recently described. (See Two new tetras named)
Hasemania nambiquara is named after the Nambiquara, a group of indigenous people from the upper Rio Tapajos in the vicinity of the type locality.
The new species has both a dark band and a dark humeral spot on the body. According to the authors: "Hasemania nambiquara is distinguished from all congeners by the unique presence of a broad black band, located ventral to midlateral line, and extending from the humeral region to the caudal-fin, and by the presence of a black vertically-elongate humeral spot."
The new species also differs in having more maxillary teeth with more cusps, and a higher number of branched anal-fin rays than most congeners.
There are five other species of Hasemania: H. crenuchoides, H. maxilaris and H. melanura from the Rio Paran, the well-known silver tipped tetra, H. nana, from the Rio So Francisco, and H. hanseni from an unknown locality in the state of Gois, Brazil. Hasemania nambiquara is the first record of this genus from the Amazon River drainage.
The new species shares with other Hasemania species in lacking an adipose fin, but the authors state that "...the new species is described herein in Hasemania because it fits best in the traditional diagnosis of the genus..." and that "...the monophyly of Hasemania based solely on the lack of an adipose fin has been questioned by several authors...".
The authors also note that two species of Hyphessobrycon, H. taurocephalus and H. negodagua, have been described as lacking an adipose fin, thereby implying that the taxonomy of both genera requires further research.
For more information, see the paper: Bertaco, VA and LR Malabarba (2007) A new species of Hasemania from the upper Rio Tapajs drainage, Brazil (Teleostei: Characiformes: Characidae). Copeia 2007 (2), 350"354.