Juan Marcos Mirande

Phylogeny of the family Characidae (Teleostei: Characiformes): from characters to taxonomy

The family Characidae is the most diverse among Neotropical fishes. Systematics of this family are mainly based on pre-cladistic papers, and only recently a phylogenetic hypothesis for Characidae was proposed by the author. That phylogeny was based on 360 morphological characters studied for 160 species, including representatives of families related to Characidae. This paper is based on that phylogenetic analysis, with the analyzed characters described herein and documented, accompanied by comparisons of their definition and coding in previous papers. Synapomorphies of each node of the proposed phylogeny are listed, comparisons with previous classifications provided, and autapomorphies of the analyzed species listed. Taxonomic implications of the proposed classification and the position of the incertae sedis genera within Characidae are discussed. A discussion of the phylogenetic information of the characters used in the classical systematics of the Characidae is provided.

Phylogenetic relationships of the enigmatic Carlastyanax aurocaudatus (Eigenmann) with remarks on the phylogeny of the Stevardiinae (Teleostei: Characidae)

The monotypic genus Carlastyanax Gery was defined to include Astyanax aurocaudatus, a morphologically odd species having, among other features, four teeth in the posterior premaxillary row and eight branched dorsal-fin rays. Later on, the characters used to define Carlastyanax were considered as invalid and this genus was synonymized with Astyanax. In this paper, we include Astyanax aurocaudatus in a phylogeny of the Characidae and obtain a sister-group relationship between this species and Creagrutus, within the Stevardiinae. The resurrection of Carlastyanax as a valid genus is therefore proposed. The analysis presented is the largest phylogeny of the Stevardiinae so far published. Relationships of this subfamily are also discussed.

Combined phylogeny of ray‐finned fishes (Actinopterygii) and the use of morphological characters in large‐scale analyses

This study evaluates the phylogeny of ray‐finned fishes (Actinopterygii) combining most available information (44 markers from nuclear and mitochondrial DNA and 274 morphological characters). The molecular partition of the dataset was produced through a pipeline (GB‐to‐TNT) that allows the fast building of large matrices from GenBank format. The analysed dataset has 8104 species, including representatives of all orders and 95% of the 475 families of Actinopterygii, making it the most diverse phylogenetic dataset analysed to date for this clade of fishes. Analysed morphological characters are features historically considered diagnostic for families or orders, which can be unequivocally coded from the literature. Analyses are by parsimony under several weighting schemes. General results agree with previous classifications, especially for groups with better gene sampling and those long thought (from morphological evidence) to be monophyletic. Many clades have low support and some orders are not recovered as monophyletic. Additional data and synthetic studies of homology are needed to obtain synapomorphies and diagnoses for most clades.

Jenynsia luxata, a new species from Northwestern Argentina, with additional observations of J. maculata Regan and phylogeny of the genus (Cyprinodontiformes: Anablepidae)

Jenynsia luxata, a new species from northwestern Argentina, is described. This species is diagnosable from all other Jenynsia by the medial processes of left and right pelvic bones relatively reduced and separated from each other. The new species resembles J. multidentata, but it is further distinguished from this species by the absence of a swelling between the urogenital opening and the anterior base of the anal fin in females and details of coloration. Phylogenetic analyses, both under implied and equal weighting, recover the subgenera Plesiojenynsia and Jenynsia as monophyletic units. New information on previously missing characters of Jenynsia maculata is added. These data and phylogenetic characters coded for the new species herein described contribute to a better resolution of the phylogenetic relationships within the subgenus Jenynsia, which is herein supported by additional synapomorphies relative to previous phylogenies.

Gephyrocharax torresi (Characiformes: Characidae: Stevardiinae), a new species from the río Cascajales basin, río Magdalena system, Colombia

A new species of Gephyrocharax is described from the rio Cascajales basin, a tributary of the rio La Colorada, rio Magdalena system, Colombia. The new species is distinguished from its congeners, exceptG. melanocheir, by the absence of an adipose fin in most specimens and by the possession of a lateral branched pectoral-fin ray in males with a distal fan-shaped structure with minute bony hooks and a dark blotch or a few scattered dark brown chromatophores along its branches. The new species differs from G.melanocheir by the absence of an intense black pigmentation at the base of the anterior five dorsal-fin rays, the number of vertebrae (40-41vs. 38-39), the frontals contacting each other anterior to the epiphyseal bar in adults (vs. the absence of contact), the posterior margin of the mesethmoid straight in its central portion (vs. strongly concave at this point), the pouch scale of mature males reaching caudal-fin ray 11 or the area between caudal-fin rays 11 and 12 (vs. reaching only to caudal-fin ray 10 or the area between caudal-fin rays 9 and 10), the number of minute terminal branches of the lateral branched pectoral-fin ray of mature males (60-88 vs. 28-54), a longer black lateral stripe along the body in males (reaching to the base of the caudal-fin rays vs. reaching the middle of the length of the caudal peduncle), and the snout length (28.3-31.8% HLvs. 22.2-28.0% HL). The diagnosis ofGephyrocharax is modified to include species with the adipose fin variably present

Phycocharax rasbora, a new genus and species of Brazilian tetra (Characiformes: Characidae) from Serra do Cachimbo, rio Tapajós basin

A new genus and species of characid fish is described from rio Braço Norte, a tributary of rio Teles Pires, Tapajós basin, Mato Groso, Brazil. The new taxa can be diagnosed from the remaining characids by a unique combination of characters that includes the presence of a single row of relatively compressed premaxillary teeth, large teeth with four to nine cusps on premaxillary and dentary, absence of pseudotympanum, incomplete lateral line with 7–13 pored scales, sexually-dimorphic males with distal margin of anal fin approximately straight, and presence of a nearly triangular and horizontally elongated blotch from the posterior half of the body to caudal peduncle. The most parsimonious phylogenetic hypothesis, using morphological data, recovered the new genus and species in a clade including Paracheirodon axelrodi and Hyphessobrycon elachys.

Living in the waterfalls: A new species of Trichomycterus (Siluriformes: Trichomycteridae) from Tabay stream, Misiones, Argentina

A new species assigned to the genus Trichomycterus from the area of the waterfalls of Tabay stream, Paraná River basin, Misiones, Argentina, is described. Trichomycterus ytororo sp. nov. is distinguished from all other species in the genus by the presence of 31–35 dorsal procurrent caudal-fin rays and the combination of some external characters such as: coloration, number of pectoral–fin rays and pores of the laterosensory canals. The new taxon belongs to a presumably monophyletic group of species composed of T. crassicaudatus, T. igobi, and T. stawiarski based on the presence of 24 or more thickly ossified and rigid procurrent caudal-fin rays with a slender distal tip extending along the tips of at least ten neural spines.

Gross anatomy and histology of the alimentary system of Characidae (Teleostei: Ostariophysi: Characiformes) and potential phylogenetic information

Un estudio comparado de la morfologia del tracto alimentario y el higado de siete especies seleccionadas correspondientes a los principales clados de la familia Characidae es presentada aqui. Tres nuevos conjuntos de caracteres correspondientes a 1) anatomia gruesa del tracto alimentario, 2) histologia del tracto alimentario y 3) anatomia gruesa del higado son evaluados aqui como potenciales fuentes de informacion para futuros estudios filogeneticos de los Characidae. No se observo una variacion intraespecifica considerable a nivel histologico y consecuentemente esta fuente no es considerada como informativa filogeneticamente al nivel taxonomico analizado. En contraste, la anatomia gruesa del higado y el tracto alimentario presentaron una variacion interespecifica importante mientras que una relativamente homogenea variacion intraespecifica fue observada. Estos caracteres son optimizados en topologias de arboles de analisis filogeneticos previos y su evolucion y potencial relacion con caracteristicas ecologicas son discutidas.

First record of Astyanax puka Mirande, Aguilera & Azpelicueta, 2007 (Teleostei: Characidae) in Juramento River basin, Salta, Argentina

Astyanax puka was described from the endorheic Rio Sali basin, Argentina, and it was not previously recorded elsewhere, being considered until now as endemic from that basin. Herein we record for the first time this species in the Rio Juramento basin, Rio de La Plata system.

Morphology, molecules and the phylogeny of Characidae (Teleostei, Characiformes)

This is the most comprehensive phylogenetic analysis of the Characidae to date and the first large‐scale hypothesis of the family, combining myriad morphological data with molecular information. A total of 520 morphological characters were analysed herein, of which 98 are newly defined. Among the analysed taxa, 259 species were coded by examining specimens, three fossil species were coded from the literature, one species was coded almost completely from published figures, 122 were partially coded from the literature, and 88 were analysed exclusively from molecular data. The total number of species in the analysed dataset is 473. Analyses were made by parsimony under equal and extended implied weighting with a broad range of parameters. The final hypothesis was selected using a stability criterion that chooses among the most parsimonious trees of all searches. It was found by weighting molecular characters with the average homoplasy of entire partitions (markers). The resulting hypothesis is congruent with previous molecular‐based phylogenies of the family. The Characidae are monophyletic, with four main clades: the Spintherobolinae new subfamily; an expanded Stethaprioninae including the Grundulini, Gymnocharacini, Rhoadsiini and Stethaprionini; the Stevardiinae; and a clade composed of the Aphyocharacinae, Characinae, Cheirodontinae, Exodontinae and Tetragonopterinae. Also, a stem Characidae was found, as formed by the Eocene–Oligocene genera †Bryconetes and †Paleotetra as successive sister groups of extant members of the family. A subfamilial classification is proposed, but deep changes in the systematics that are beyond the scope of this study are still needed to classify the Characidae into monophyletic genera.