Hypsolebias trifasciatus, a new species of annual fish (C yprinodontiformes: Rivulidae) from the rio Preto, rio São Francisco basin, northeastern Brazil

Hypsolebias trifasciatus n. sp. is described from a tempo- rary pool located on the left bank of the rio Preto, a tribu- tary of the rio Sao Francisco. It is the first species of the H. adornatus complex recorded in a tributary rather than the rio Sao Francisco main channel. This species is distin- guished from the remaining Hypsolebias species, with the exception of those belonging to the H. adornatus complex, by the high number of dorsal fin rays (27-28), and conse- quently a large dorsal fin base length, beginning consider- ably anteriorly to the middle of the body, before the verti- cal line through the pelvic fin. The new species differs from the remaining species of the H. adornatus complex by the color pattern of the anal fin, which consists in longitudi- nal, alternating three yellow and three black stripes (vs. stripes absent in the remaining Hypsolebias of the H. ador- natus complex, or relatively inconspicuous 2 yellow stripes and 2-3 gray stripes in H. lopesi), and a unique pattern of the dorsal-fin color in males, with the presence of two groups of 3-4 irregularly-shaped, large yellow spots (vs. ab- sence of a such pattern in the remaining Hypsolebias of the H. adornatus-group). Zusammenfassung Hypsolebias trifasciatus n. sp. wird von einem zeitbegrenzten