Crenicichla taikyra, new species, is described from the middle río Paraná, Argentina. Crenicichla... more Crenicichla taikyra, new species, is described from the middle río Paraná, Argentina. Crenicichla taikyra is distinguished from the other species of the genus by the following combination of characters: lower pharyngeal tooth plate stout, bearing molariform teeth, ascending arm of premaxilla longer than the dentigerous arm, posterior edge of preoperculum serrated, a well developed suborbital stripe, and absence of scattered dark dots on flanks. Molariform teeth on pharyngeal jaws is a derived character among Crenicichla species, however this character state has appeared several times in unrelated species.
Crenicichla taikyra, new species, is described from the middle río Paraná, Argentina. Crenicichla... more Crenicichla taikyra, new species, is described from the middle río Paraná, Argentina. Crenicichla taikyra is distinguished from the other species of the genus by the following combination of characters: lower pharyngeal tooth plate stout, bearing molariform teeth, ascending arm of premaxilla longer than the dentigerous arm, posterior edge of preoperculum serrated, a well developed suborbital stripe, and absence of scattered dark dots on flanks. Molariform teeth on pharyngeal jaws is a derived character among Crenicichla species, however this character state has appeared several times in unrelated species.
Oligosarcus amome is described from tributaries of the arroyo Yabotí-Guazú, río Uruguay basin, Mi... more Oligosarcus amome is described from tributaries of the arroyo Yabotí-Guazú, río Uruguay basin, Misiones Province, Argentina. This new species can be distinguished from all its congeners by the following combination of characters: presence of two conspicuous series of teeth on premaxilla bearing pentacuspidate teeth in the outer series. Oligosarcus amome is the sister taxon of all remaining analyzed species of the genus excepting O. itau.
A new species of Crenicichla, C. ypo, is described from the Arroyo Urugua-í, a left-hand tributar... more A new species of Crenicichla, C. ypo, is described from the Arroyo Urugua-í, a left-hand tributary of the middle Paraná River, Misiones province, Argentina. The new species is recognized by 6 to 8 irregular blotches along the upper lateral line, absence of scattered dark spots on flanks, low number (47-55) of E1 scales, and a slightly prognathous lower jaw. Females have a distinctive coloration of the dorsal fin, with a wide black longitudinal stripe on the distal portion with an equally wide red stripe below it.
First multilocus analysis of the largest Neotropical cichlid genus Crenicichla combining mitochon... more First multilocus analysis of the largest Neotropical cichlid genus Crenicichla combining mitochondrial (cytb, ND2, 16S) and nuclear (S7 intron 1) genes and comprising 602 sequences of 169 specimens yields a robust phylogenetic hypothesis. The best marker in the combined analysis is the ND2 gene which contributes throughout the whole range of hierarchical levels in the tree and shows weak effects of saturation at the 3rd codon position. The 16S locus exerts almost no influence on the inferred phylogeny. The nuclear S7 intron 1 resolves mainly deeper nodes. Crenicichla is split into two main clades: (1) Teleocichla, the Crenicichla wallacii group, and the Crenicichla lugubris-Crenicichla saxatilis groups (''the TWLuS clade''); (2) the Crenicichla reticulata group and the Crenicichla lacustris group-Crenicichla macrophthalma (''the RMLa clade''). Our study confirms the monophyly of the C. lacustris species group with very high support. The biogeographic reconstruction of the C. lacustris group using dispersal-vicariance analysis underlines the importance of ancient barriers between the middle and upper Paraná River (the Guaíra Falls) and between the middle and upper Uruguay River (the Moconá Falls). Our phylogeny recovers two endemic species flocks within the C. lacustris group, the Crenicichla missioneira species flock and the herein discovered Crenicichla mandelburgeri species flock from the Uruguay and Paraná/Iguazú Rivers, respectively. We discuss putative sympatric diversification of trophic traits (morphology of jaws and lips, dentition) and propose these species flocks as models for studying sympatric speciation in complex riverine systems. The possible role of hybridization as a mechanism of speciation is mentioned with a recorded example (Crenicichla scottii).
Aim We present a molecular phylogenetic and biogeographical analysis of the Mesoamerican cichlid ... more Aim We present a molecular phylogenetic and biogeographical analysis of the Mesoamerican cichlid fishes (Cichlidae: Cichlasomatinae: Heroini), a dominant part of the freshwater biodiversity of the region. Based on these analyses we investigate the spatial and temporal origins and diversification of the group.
Background: Annelida is one of the major protostome phyla, whose deep phylogeny is very poorly un... more Background: Annelida is one of the major protostome phyla, whose deep phylogeny is very poorly understood. Recent molecular phylogenies show that Annelida may include groups once considered separate phyla (Pogonophora, Echiurida, and Sipunculida) and that Clitellata are derived polychaetes. SThe "total-evidence" analyses combining morphological and molecular characters have been published for a few annelid taxa. No attempt has yet been made to analyse simultaneously morphological and molecular information concerning the Annelida as a whole.
Crenicichla taikyra, new species, is described from the middle río Paraná, Argentina. Crenicichla... more Crenicichla taikyra, new species, is described from the middle río Paraná, Argentina. Crenicichla taikyra is distinguished from the other species of the genus by the following combination of characters: lower pharyngeal tooth plate stout, bearing molariform teeth, ascending arm of premaxilla longer than the dentigerous arm, posterior edge of preoperculum serrated, a well developed suborbital stripe, and absence of scattered dark dots on flanks. Molariform teeth on pharyngeal jaws is a derived character among Crenicichla species, however this character state has appeared several times in unrelated species.
Crenicichla taikyra, new species, is described from the middle río Paraná, Argentina. Crenicichla... more Crenicichla taikyra, new species, is described from the middle río Paraná, Argentina. Crenicichla taikyra is distinguished from the other species of the genus by the following combination of characters: lower pharyngeal tooth plate stout, bearing molariform teeth, ascending arm of premaxilla longer than the dentigerous arm, posterior edge of preoperculum serrated, a well developed suborbital stripe, and absence of scattered dark dots on flanks. Molariform teeth on pharyngeal jaws is a derived character among Crenicichla species, however this character state has appeared several times in unrelated species.
Oligosarcus amome is described from tributaries of the arroyo Yabotí-Guazú, río Uruguay basin, Mi... more Oligosarcus amome is described from tributaries of the arroyo Yabotí-Guazú, río Uruguay basin, Misiones Province, Argentina. This new species can be distinguished from all its congeners by the following combination of characters: presence of two conspicuous series of teeth on premaxilla bearing pentacuspidate teeth in the outer series. Oligosarcus amome is the sister taxon of all remaining analyzed species of the genus excepting O. itau.
A new species of Crenicichla, C. ypo, is described from the Arroyo Urugua-í, a left-hand tributar... more A new species of Crenicichla, C. ypo, is described from the Arroyo Urugua-í, a left-hand tributary of the middle Paraná River, Misiones province, Argentina. The new species is recognized by 6 to 8 irregular blotches along the upper lateral line, absence of scattered dark spots on flanks, low number (47-55) of E1 scales, and a slightly prognathous lower jaw. Females have a distinctive coloration of the dorsal fin, with a wide black longitudinal stripe on the distal portion with an equally wide red stripe below it.
First multilocus analysis of the largest Neotropical cichlid genus Crenicichla combining mitochon... more First multilocus analysis of the largest Neotropical cichlid genus Crenicichla combining mitochondrial (cytb, ND2, 16S) and nuclear (S7 intron 1) genes and comprising 602 sequences of 169 specimens yields a robust phylogenetic hypothesis. The best marker in the combined analysis is the ND2 gene which contributes throughout the whole range of hierarchical levels in the tree and shows weak effects of saturation at the 3rd codon position. The 16S locus exerts almost no influence on the inferred phylogeny. The nuclear S7 intron 1 resolves mainly deeper nodes. Crenicichla is split into two main clades: (1) Teleocichla, the Crenicichla wallacii group, and the Crenicichla lugubris-Crenicichla saxatilis groups (''the TWLuS clade''); (2) the Crenicichla reticulata group and the Crenicichla lacustris group-Crenicichla macrophthalma (''the RMLa clade''). Our study confirms the monophyly of the C. lacustris species group with very high support. The biogeographic reconstruction of the C. lacustris group using dispersal-vicariance analysis underlines the importance of ancient barriers between the middle and upper Paraná River (the Guaíra Falls) and between the middle and upper Uruguay River (the Moconá Falls). Our phylogeny recovers two endemic species flocks within the C. lacustris group, the Crenicichla missioneira species flock and the herein discovered Crenicichla mandelburgeri species flock from the Uruguay and Paraná/Iguazú Rivers, respectively. We discuss putative sympatric diversification of trophic traits (morphology of jaws and lips, dentition) and propose these species flocks as models for studying sympatric speciation in complex riverine systems. The possible role of hybridization as a mechanism of speciation is mentioned with a recorded example (Crenicichla scottii).
Aim We present a molecular phylogenetic and biogeographical analysis of the Mesoamerican cichlid ... more Aim We present a molecular phylogenetic and biogeographical analysis of the Mesoamerican cichlid fishes (Cichlidae: Cichlasomatinae: Heroini), a dominant part of the freshwater biodiversity of the region. Based on these analyses we investigate the spatial and temporal origins and diversification of the group.
Background: Annelida is one of the major protostome phyla, whose deep phylogeny is very poorly un... more Background: Annelida is one of the major protostome phyla, whose deep phylogeny is very poorly understood. Recent molecular phylogenies show that Annelida may include groups once considered separate phyla (Pogonophora, Echiurida, and Sipunculida) and that Clitellata are derived polychaetes. SThe "total-evidence" analyses combining morphological and molecular characters have been published for a few annelid taxa. No attempt has yet been made to analyse simultaneously morphological and molecular information concerning the Annelida as a whole.
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