Description of a new species of the Melanorivulus pictus species-group (Cyprinodontiformes: Rivulidae) from the Rio Paraná basin in Brazil.

A new species of the genus Melanorivulus belonging to the Melanorivulus pictus species group is herein described, from a tributary of the Rio Grande, Rio Paraná basin, São Paulo State, Brazil. The new species can be distinguished from all other species of the Melanorivulus pictus species group by the unique presence of sides of body of males light bluish gray with 10-12 oblique red bars, 8 of which chevron-like, bifurcated and complete, i.e., running from dorsum to ventral area, and 2-4 incomplete, with vertices of the chevron-like bars along midbody, pointing forward. Comments on the putative relationships of the new species, as well as concerning its conservation status, are presented.

Review of the family Rivulidae (Cyprinodontiformes, Aplocheiloidei) and a molecular and morphological phylogeny of the annual fish genus Austrolebias Costa 1998

The family Rivulidae is the fourth most diverse clade of Neotropical fishes. Together with some genera of the related African family Nothobranchiidae, many rivulids exhibit a characteristic annual life cycle, with diapausing eggs and delayed embryonic development, which allows them to survive in the challenging seasonal ponds that they inhabit. Rivulidae also includes two species known as the only the self-fertilizing vertebrates and some species with internal fertilization. The first goal of this article is to review the systematics of the family considering phylogenetic relationships and synapomorphies of subfamilial clades, thus unifying information that is dispersed throughout the literature. From this revision, it is clear that phylogenetic relationships within Rivulidae are poorly resolved, especially in one of the large clades that compose it, the subfamily Rivulinae, where conflicting hypotheses of relationships of non-annual and annual genera are evident. The second goal of this work is to present an updated phylogenetic hypothesis (based on mitochondrial, nuclear, and morphological information) for one of the most speciose genus of Rivulidae, Austrolebias. Our results confirm the monophyly of the genus and of some subgeneric clades already diagnosed, but propose new relationships among them and their species composition, particularly in the subgenus Acrolebias.

a familia Rivulidae es el cuarto clado más diverso dentro de los peces Neotropicales. Junto con algunos géneros de la familia Nothobranchiidae, muchos rivulidos presentan un característico ciclo de vida anual, con huevos resistentes a la desecación y embriones con diapausas que les permiten sobrevivir en los ambientes estacionales donde habitan. Los Rivulidae presentan también dos especies consideradas como los únicos vertebrados hermafroditas suficientes y algunas especies con inseminación interna. El primer objetivo de este artículo es actualizar la sistemática de la familia considerando las relaciones filogenéticas y las sinapomorfías de los clados que la componen, reuniendo información que se encuentra dispersa en la literatura. De esta revisión surge que las relaciones filogenéticas dentro de Rivulidae están todavía sin resolver, especialmente en uno de los grandes clados que la componen, la subfamilia Rivulinae, donde relaciones conflictivas entre géneros anuales y no anuales son evidentes. El segundo objetivo de este trabajo es presentar una hipótesis filogenética, basada en datos morfológicos, mitocondriales y nucleares, de uno de los géneros más diversos de la familia, el género Austrolebias. Nuestros resultados confirman la monofilia del género y de algunos clados subgenéricos previamente definidos, y propone nuevas relaciones entre ellos, particularmente de las especies del subgénero Acrolebias(AU)

A new annual fish of the genus Simpsonichthys (Cyprinodontiformes: Cynolebiidae) from the upper Rio Jequitinhonha basin, Brazil.

A new species of Simpsonichthys is described from the upper rio Jequitinhonha basin, Minas Gerais, eastern Brazil. It is diagnosed from all congeners by presenting an A-patterned frontal squamation. Additionally, males of the new species differs from all congeners by the color pattern of body, the color of iris, the absence of contact organs in the pectoral fin, presence of scales on anal-fin base, pectoral-fin length, caudal fin length, and eye diameter. Females of the new species can be diagnosed from remaining congeners by the pectoral-fin length. The conservation status of the new species is evaluated. Comments on the relationships of the new species within the genus Simpsonichthys are presented.

Description of two new species of annual fishes of the Hypsolebias antenori species group (Cyprinodontiformes: Rivulidae), from Northeast Brazil.

The Hypsolebias antenori species group comprises a monophyletic clade of annual fishes occurring in the semi-arid region of Northeastern Brazil. Most species of this group are found in the Rio São Francisco basin, but there are three species that inhabit small coastal basins. Hypsolebias faouri new species, is described from a temporary pool located near Rio Preto, a tributary of the Rio São Francisco, and Hypsolebias martinsi new species, is described from an annual pool near Rio Icaraizinho, a coastal drainage. Molecular data corroborates the monophyly of Hypsolebias and both new species.

Spectrolebias brousseaui (Cyprinodontiformes: Rivulidae: Cynolebiatinae), a new annual fish from the upper río Mamoré basin, Bolivia

Spectrolebias brousseaui is described from a temporary pool from the upper río Mamoré basin, Departamento Santa Cruz, Bolivia. The new species is distinguished from all congeners, by the overall dark blue coloration on the posterior two-thirds of body with bright blue iridescent spots vertically aligned in males. Spectrolebias brousseaui differs from all other species of the genus, except S. filamentosus, for having pelvic fins separated by a space (vs. pelvic fins in contact), long filaments at the tip of the dorsal and anal fins in males (vs. absence of filaments or presence only on dorsal fin in S. semiocellatus and S. inaequipinnatus, or the presence on the anal fin in S. chacoensis), and presence of contact organs on the scales of the flanks in males (vs. absence of contact organs on flanks in all remaining Spectrolebias species). .

Spectrolebias brousseaui é descrita de uma poça temporária localizada na região superior da bacia do río Mamoré, departamento de Santa Cruz, Bolívia. A espécie nova distingue-se de todos os congêneres pelo padrão de cor azul escuro nos dois terços posteriores do corpo com pontos azuis claros iridescentes alinhados verticalmente em machos. Spectrolebias brousseaui difere das outras espécies do gênero, exceto S. filamentosus, por ter as nadadeiras pélvicas separadas por um espaço (vs. nadadeira pélvicas juntas), longos filamentos nas extremidades das nadadeiras dorsal e anal em machos (vs. ausência de filamentos ou a presença apenas na nadadeira dorsal em S. semiocellatus e S. inaequipinnatus, ou pela presença de filamentos na nadadeira anal em S. chacoensis), e presença de órgão de contato nas escamas do flanco em machos (vs. ausência).