Claraz y los bagres del fin del mundo

Los bagres de la Patagonia según la perspectiva de George Claraz en su “Diario de viaje de exploración al Chubut 1865-66” ¿Desde cuándo habitan la Patagonia? ¿Cuántas especies de bagres se conocen para esta región? ¿Por qué su piel es aterciopelada?Fundación Museo La Plat

First record of the hypoptopomatine genus Eurycheilichthys Reis & Schaefer, 1993 (Siluriformes, Loricariidae) from Argentina

The hypoptopomatine genus Eurycheilichthys was so far considered to be endemic to the South of Brazil. One of its species, E. pantherinus, was described from the upper Uruguay river basin. We inform about the finding of this species within the Garibaldi creek, headwater of the arroyo Yabotí Guazú. This is the first record for Argentina which is found in a tributary of the middle Uruguay river.Facultad de Ciencias Naturales y Muse

Claraz y los bagres del fin del mundo

Los bagres de la Patagonia según la perspectiva de George Claraz en su “Diario de viaje de exploración al Chubut 1865-66” ¿Desde cuándo habitan la Patagonia? ¿Cuántas especies de bagres se conocen para esta región? ¿Por qué su piel es aterciopelada?Fundación Museo La Plat

Claraz y los bagres del fin del mundo

Los bagres de la Patagonia según la perspectiva de George Claraz en su “Diario de viaje de exploración al Chubut 1865-66” ¿Desde cuándo habitan la Patagonia? ¿Cuántas especies de bagres se conocen para esta región? ¿Por qué su piel es aterciopelada?Fundación Museo La Plat

A new species of Astyanax (Characiformes, Characidae) from Uruguay river basin in Argentina, with remarks on hook presence in Characidae

In the present paper the new species Astyanax ojiara sp. n. is described, from the headwaters of Yabotí river, an affluent of Uruguay river in the province of Misiones, Argentinean northeast. A combination of characters differentiates the new species from other congeners: one heptacuspid maxillary teeth; teeth of inner premaxillary row gently expanded distally; 7-9 dentary teeth decreasing in size anteroposteriorly; males with hooks in all fins; large males with pelvic axillary scale bearing 1 to 8 hooks; 36-38 perforated scales in lateral line; 20-23 branched anal-fin rays. Number of scales in the lateral line and branched anal-fin rays, humeral spot, and low body of Astyanax ojiara sp. n. resemble those of A. eigenmanniorum, but maxillary, premaxillary and dentary teeth differ in both species. The disposition of the dentary leeth is also similar in A. taeniatus and A. giton but A. ojiara sp. n. has one heptacuspid maxillary tooth.Facultad de Ciencias Naturales y Muse

Redescription of the Eocene catfish Bachmannia chubutensis (Teleostei: Bachmanniidae) of southern South America

The Siluriformes constitutes an important monophyletic ostariophysan group of mainly freshwater fishes that occurs in almost all continents. They are extremely abundant and diverse in South America, where the oldest otophysans and siluriforms occur. We restudied two putative catfish species from the early Eocene lacustrine Tufolitas Laguna del Hunco of northwestern Patagonia, Argentina, concluding that Arius argentinus Dolgopol, 1941, is a junior synonym of Bachmannia chubutensis Dolgopol, 1941. Phylogenetic analyses were performed to show the relationships of B. chubutensis, which appears as the sister group of Diplomystes. Bachmannia chubutensis is one of the most primitive catfishes known and we based on it a new family. The family is clearly diagnosed by the presence of a anterior ventrolateral expansion of cleithrum, short maxilla with two rows of teeth, double-headed autopalatine, accessory tooth plates, very huge teeth, supraoccipital process long and acute, first and fifth vertebrae not joined to complex vertebra, neural arch of fifth and sixth vertebrae very well developed, enlarged supraneural 5, suture between ceratohyal and epihyal without interdigitations, suture between contralateral cleithra and coracoids without interdigitations, six hypurals. Individuals of B. chubutensis inhabited lakes and were preserved into fine-grained, laminated fall-out and reworked pyroclastic debris inside a caldera.Fil: Azpelicueta, María De Las Mercedes. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Departamento Científico Zoología Vertebrados; ArgentinaFil: Cione, Alberto Luis. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Paleontología Vertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentin

Phylogeography of the Neotropical catfish Pimelodus albicans (Siluriformes: Pimelodidae) from río de la Plata basin, South America, and conservation remarks

Pimelodus albicans Valenciennes, 1840 (common name "moncholo" or "bagre blanco") is an endemic species of the family Pimelodidae in the río de la Plata basin. Phylogenetic approach based on cytochrome b sequences was performed to test the existence of a unique evolutionary lineage in P. albicans and to discriminate populations units or subpopulations related to a migration behavior of this taxon in the río de la Plata basin. This study included 34 samples of P. albicans of different collecting sites in the río de la Plata estuary and in the río Arrecifes belonging to the río Paraná basin. Among 614 base pairs in the cytochrome b sequence data set, 203 were variable and 120 were phylogenetically informative sites in P. albicans. A total of twenty haplotypes, nucleotide diversity (π) = 0.032 and haplotype diversity = 0.941 were found. Tajima's test showed significant value D= -1.88 (p<0.05) rejecting the neutral mutation hypothesis for the P. albicans data set. All phylogenetic approaches showed that P. albicans included four monophyletic assemblages that were supported by high bootstrap and Bayesian posterior probability values. Minimum spanning network corroborated these groups for P. albicans haplotypes. High genetic structure was found in P. albicans by means of AMOVA analysis showing that the río Arrecifes samples constitute an isolated lineage. Moreover, the high value of genetic divergence (10%) between the río de la Plata and the río Arrecifes populations could suggest that P. albicans may be conformed by a sibling species complex. On the other hand, a degree of genetic structuring was detected among different sites of the río de la Plata. A partial isolation of the 760 site may suggest that P. albicans could migrates to different tributaries for reproduction, generating different schools of haplotypes which could mix in the río de la Plata estuary. The high nucleotide diversity found in the 765 site and the existence of gene flow with the remaining collecting sites would be concordant with the outlined hypothetic scenarios of the mixing populations in the middle of the río de la Plata estuaryFacultad de Ciencias Naturales y Muse

From icthyoarchaeology to food practices: The case of Los Tres Cerros 1 (Upper Delta of the Paraná river, Entre Ríos)

Se estudia el conjunto ictioarqueológico del sitio Los Tres Cerros 1 (1030-560 años AP) con el objetivo de discutir las prácticas de obtención, procesamiento, cocción, consumo y descarte de los recursos ícticos, así como los procesos naturales que afectaron los restos una vez depositados. Se analizó la abundancia taxonómica y anatómica junto con distintas variables tafonómicas, enfatizando el estudio de los indicadores de procesamiento. En el sitio se aprovecharon numerosas especies de Characiformes (mayormente Prochilodus lineatus y Hoplias sp.), Siluriformes (Pimelodus sp., Rhamdia quelen, Pterodoras granulosus, Trachelyopterus sp., etc.), Perciformes y Synbranchiformes. Estos recursos fueron obtenidos mediante variados métodos de captura (individual y en masa), enfocados principalmente en los sectores lénticos del paisaje fluvial. Posteriormente, fueron procesados a través de diversas operaciones (como evisceración, decapitación, fileteo, seccionamiento), tanto a los fines de integrar preparaciones consumidas in situ, como para generar productos almacenables aptos para el consumo diferido y el intercambio.Los Tres Cerros 1 (1030-560 BP) ichthyo-archaeological assemblage is analyzed in order to assess fish capture, processing, cooking, consumption and discard practices, as well as subsequent natural processes affecting bones. Taxonomic, anatomical and taphonomic studies were carried out, placing emphasis on fish processing indicators. Several species of Characiformes (mainly Prochilodus lineatus and Hoplias sp.), Siluriformes (Pimelodus sp., Rhamdia quelen, Pterodoras granulosus, Trachelyopterus sp., among others), Perciformes and Synbranchiformes were exploited at the site. These resources were obtained through various fishing methods (individual and mass capture) mainly focused on lentic fluvial environments. Afterwards, they were processed by way of numerous operations (e.g. gutting, decapitation, filleting, splitting) in order to cook meals for in situ consumption, as well as to produce storable foodstuff suitable for delayed consumption and exchange.Sociedad Argentina de Antropologí

First record of the hypoptopomatine genus Eurycheilichthys Reis & Schaefer, 1993 (Siluriformes, Loricariidae) from Argentina

The hypoptopomatine genus Eurycheilichthys was so far considered to be endemic to the South of Brazil. One of its species, E. pantherinus, was described from the upper Uruguay river basin. We inform about the finding of this species within the Garibaldi creek, headwater of the arroyo Yabotí Guazú. This is the first record for Argentina which is found in a tributary of the middle Uruguay river.Facultad de Ciencias Naturales y Muse

A new species of Astyanax (Characiformes, Characidae) from Uruguay river basin in Argentina, with remarks on hook presence in Characidae

In the present paper the new species Astyanax ojiara sp. n. is described, from the headwaters of Yabotí river, an affluent of Uruguay river in the province of Misiones, Argentinean northeast. A combination of characters differentiates the new species from other congeners: one heptacuspid maxillary teeth; teeth of inner premaxillary row gently expanded distally; 7-9 dentary teeth decreasing in size anteroposteriorly; males with hooks in all fins; large males with pelvic axillary scale bearing 1 to 8 hooks; 36-38 perforated scales in lateral line; 20-23 branched anal-fin rays. Number of scales in the lateral line and branched anal-fin rays, humeral spot, and low body of Astyanax ojiara sp. n. resemble those of A. eigenmanniorum, but maxillary, premaxillary and dentary teeth differ in both species. The disposition of the dentary leeth is also similar in A. taeniatus and A. giton but A. ojiara sp. n. has one heptacuspid maxillary tooth.Facultad de Ciencias Naturales y Muse