A new species of Hasemania tetra from northeastern Brazil has been described by Brazilian ichthyologists in the most recent issue of the journal Neotropical Ichthyology.
Angela Zanata and Jane Serra name the new species Hasemania piatan, after the county where the species is found (Piatã).
Hasemania piatan is distinguished from congeners in having 18 principal caudal-fin rays and a combination of seven branched dorsal-fin rays, six branched pelvic-fin rays, scales not covering anal-fin base, five infraorbitals, a humeral blotch, 10–13 branched anal-fin rays, 27–32 scales on the longitudinal series, 10–12 circumpeduncular scales, and one to three maxillary teeth.
The new species is known from the upper rio de Contas drainage in northeastern Brazil, where it inhabits streams with clear water, a moderate current and a sandy substrate. An analysis of stomach contents revealed insect fragments and large quantities of filamentous algae.
For more information, see the paper: Zanata, AM and JP Serra (2010) Hasemania piatan, a new characid species (Characiformes: Characidae) from headwaters of Rio de Contas, Bahia, Brazil. Neotropical Ichthyology 8, pp. 21–26.