A new mouth brooder species of Gymnogeophagus with hypertrophied lips (Cichliformes: Cichlidae)

A new mouth breeder species of Gymnogeophagus is described from a tributary of the río Uruguay. It is distinguished from most species of the genus by the presence of hypertrophied lips, and from G. labiatus and G. pseudolabiatus by the color pattern. The presence of successive allopatric species of the Gymnogeophagus gymnogenys clade inhabiting the tributaries of the río Uruguay is discussed.Una nueva especie incubadora bucal de Gymnogeophagus es descripta de un tributario del Río Uruguay. Se distingue de la mayoría de las especies del género por la presencia de labios hipertrofiados, y de G. labiatus y G. pseudolabiatus por su patrón de coloración. Se discute la presencia de sucesivas especies alopátricas del clado Gymnogeophagus gymnogenys habitando los tributarios del Río Uruguay

Morphological variability in populations of the fiddler crab Leptuca uruguayensis (Nobili, 1901) (Crustacea, Decapoda, Ocypodidae) from South America

Um estudo comparativo sobre o tamanho e a forma de Leptuca uruguayensis foi realizado entre as populações do Rio das Garças, Brasil (BP) e do Rio Solís Grande, Uruguai (UP). O tamanho do início da maturidade sexual, também foi estimado para UP. Foi analisado um total de 36 indivíduos para BP e 387 para UP. Para a análise do crescimento relativo, a largura da carapaça (LC) para ambos os sexos, comprimento do maior quelípodo (CMQ) dos machos e a largura do abdome (LA) das fêmeas foram mensurados. O tamanho da carapaça e do quelípodo foi maior em UP. A forma também diferiu, sendo a carapaça de UP mais ampla do que BP; rostro projetado para a frente e margem posterior posicionada mais anteriormente; o quelípodo de UP também foi mais amplo do que BP. Em UP, a LC variou de 4,28-19,5 mm (machos) e 2,53-16,3 mm (fêmeas); o CMQ variou de 1,79-31,60 mm (machos) e a LA de 0,80-8,53 mm (fêmeas). O início da maturidade sexual para UP foi estimado em 12,20 mm LC (machos) e 7,81 mm (fêmeas). Essas diferenças podem indicar que variáveis abióticas estão atuando distintamente nas duas localidades.A comparative study on size and shape of Leptuca uruguayensis was carried out between populations from Garças River, Brazil (BP), and Solís Grande River, Uruguay (UP). The size of the onset of sexual maturity was also estimated for UP. A total of 36 crabs BP and 387 crabs UP were analyzed. In the relative growth analysis, carapace width (CW) for both sexes, major cheliped length (LMC) for males and abdomen width (AW) for females were measured. The centroid size of carapace (1.40±0.19 cm BP and 1.88±0.30 cm UP) and cheliped (1.16±0.22 cm BP and 1.58±0.45 cm UP) differed significantly (

First Record of Loricariichthys edentatus (Siluriformes: Loricariidae) in the Paraná River

Campañas realizadas al noreste de Argentina en el río Paraná revelaron la presencia de la vieja del agua Loricariichthys edentatus Reis & Pereira 2000, que representa el primer registro de esta especie para esa cuenca.Recent expeditions to northeastern Argentina in the Paraná River revealed the presence of the armored catfish Loricariichthys edentatus Reis & Pereira 2000, which represents the first record of this species to that basin.Fil: Teran, Guillermo Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Aguilera, Gaston. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Serra, Wilson Sebastián. Museo Nacional de Historia Natural; UruguayFil: Ruiz Diaz, Federico Jose. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mirande, Juan Marcos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentin

Peces bajo tierra : Peces estacionales que pueden pasar la mayor parte de su vida enterrados, joyas de nuestra naturaleza

Probablemente el último lugar en el que uno esperaría encontrar un pez es fuera del agua, y mucho menos enterrado bajo tierra. Sin embargo, hay unos peces que viven en charcas de lluvia que se secan completamente durante largos periodos y sobreviven gracias a que tienen huevos que resisten el desecamiento enterrados en el fondo del charco. Con las llegadas de las lluvias estas charcas se llenan de agua y pequeños peces de colores eclosionan de huevos que yacían “dormidos” bajo tierra a la espera de las lluvias. Por esta razón muchas veces la gente asume que estos peces caen del cielo con la lluvia.Instituto de Limnología "Dr. Raúl A. Ringuelet

On the presence of the poorly documented Hypostomus isbrueckeri Reis, Weber & Malabarba, 1990 (Siluriformes: Loricariidae) in Argentina and extension of its distribution range

Hypostomus Lacépède is the most speciose loricariid genus, including about 150 valid species (Fricke et al. 2022). It has a wide distribution in the Neotropical basins, occurring from Central America to the Salado River, South of the La Plata River in the Province of Buenos Aires, Argentina (Ringuelet 1975; López 1992; Fricke et al. 2022). In Argentina the genus was recorded for the first time in 1876 (Weyenbergh 1876; Koerber & Weber 2014), and there are currently 26 species considered as present or probably present in the country (Cardoso et al. 2011, 2012, 2016, 2019; Koerber & Weber 2014; Terán et al. 2020). Some of these species are poorly documented in the literature since the records lack traceable voucher specimens, detailed descriptions and photographs, necessary conditions to make reliable and falsifiable faunal records (Serra et al. 2021). In recent collection campaigns in the Uruguay river basin in the province of Corrientes (Argentina), we collected specimens of Hypostomus that were identified by comparison with collection specimens and literature information.Fil: Teran, Guillermo Enrique. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Serra, Wilson Sebastián. Ministerio de Educación y Cultura. Museo Nacional de Historia Natural; Uruguay. Centro Universitario Regional Este; UruguayFil: Ruiz Diaz, Federico Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias. Instituto de Ictiología del Nordeste; ArgentinaFil: Alonso, Felipe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Bugeau, Horacio Baltazar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Aguilera, Gaston. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Mirande, Juan Marcos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentin

Description of a new species of the Neotropical cichlid genus Gymnogeophagus Miranda Ribeiro, 1918 (Teleostei: Cichliformes) from the Middle Paraná basin, Misiones, Argentina

Gymnogeophagus jaryi, new species, is described from Southern tributaries of the Middle Paraná basin in Misiones. It can be distinguished from all other members of the genus, except from G. australis and G. caaguazuensis, by the presence of a hyaline to grey anterior portion of the dorsal fin. Gymnogeophagus jaryi differs from G. caaguazuensis by a longer caudal peduncle, caudal fin not lyrate, central portion of scales on dorsal portion of trunk light iridescent blue and by white spots in soft portion of dorsal fin in adult males, and from G. australis by the light iridescent blue coloration of central portion of scales on the dorsal portion of trunk and tail, and by the lack of scales on the soft portion of the dorsal fin. Additionally, it can be diagnosed by the following unique combination of characters: 10-11 dorsal-fin branched rays, 27-30 E1 scales, absence of lips thickening, and, in males, by the possession of a hump in adults, caudal fin not lyrate, presence of large white spots forming transversal stripes distally and in anterior area of the dorsal fin's soft portion, central area of scales on the dorsal portion of the trunk light iridescent blue, lack of scales on the base of the dorsal fin's soft portion, absence of a conspicuous and oblique dark band from the eye to the anterior border of the head, anterior portion of dorsal fin hyaline to grey, scales of the midlateral spot each bearing a semicircular light blue blotch, head hump starting at the horizontal through the eyes, concave anterior profile in lateral view, base of unpaired fins yellow, and whitish hyaline spots on caudal fin. The new species, based on mtDNA phylogeny, is the sister species of G. caaguazuensis from the Paraguay basin and is closely related to G. australis.Instituto de Limnología "Dr. Raúl A. Ringuelet

A recipe for scavenging in vertebrates - the natural history of a behaviour

AK was funded by the Irish Research Council GOIP/2015/81, KH was funding by Science Foundation Ireland. T.G. acknowledges support from European Research Council under the European Union’s Seventh Framework Programme (FP/2007–2013)/ERC Grant Agreement number 311092 awarded to Martin D. Brazeau.Despite its prevalence, the importance of scavenging to carnivores is difficult to ascertain in modern day forms and impossible to study directly in extinct species. Yet, there are certain intrinsic and environmental features of a species that push it towards a scavenging lifestyle. These can be thought of as some of the principal parameters in optimal foraging theory namely, encounter rate and handling time. We use these components to highlight the morphologies and environments that would have been conducive to scavenging over geological time by focusing on the dominant vertebrate groups of the land, sea and air. The result is a synthesis on the natural history of scavenging. The features that make up our qualitative scale of scavenging can be applied to any given species and allow us to judge the likely importance of this foraging behaviour.PostprintPeer reviewe

A new mouth brooder species of Gymnogeophagus with hypertrophied lips (Cichliformes: Cichlidae)

ABSTRACT A new mouth breeder species of Gymnogeophagus is described from a tributary of the río Uruguay. It is distinguished from most species of the genus by the presence of hypertrophied lips, and from G. labiatus and G. pseudolabiatus by the color pattern. The presence of successive allopatric species of the Gymnogeophagus gymnogenys clade inhabiting the tributaries of the río Uruguay is discussed

On the presence of the poorly documented Hypostomus isbrueckeri Reis, Weber & Malabarba, 1990 (Siluriformes: Loricariidae) in Argentina and extension of its distribution range

Hypostomus Lacépède is the most speciose loricariid genus, including about 150 valid species (Fricke et al. 2022). It has a wide distribution in the Neotropical basins, occurring from Central America to the Salado River, South of the La Plata River in the Province of Buenos Aires, Argentina (Ringuelet 1975; López 1992; Fricke et al. 2022). In Argentina the genus was recorded for the first time in 1876 (Weyenbergh 1876; Koerber & Weber 2014), and there are currently 26 species considered as present or probably present in the country (Cardoso et al. 2011, 2012, 2016, 2019; Koerber & Weber 2014; Terán et al. 2020). Some of these species are poorly documented in the literature since the records lack traceable voucher specimens, detailed descriptions and photographs, necessary conditions to make reliable and falsifiable faunal records (Serra et al. 2021). In recent collection campaigns in the Uruguay river basin in the province of Corrientes (Argentina), we collected specimens of Hypostomus that were identified by comparison with collection specimens and literature information.Fil: Teran, Guillermo Enrique. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Serra, Wilson Sebastián. Ministerio de Educación y Cultura. Museo Nacional de Historia Natural; Uruguay. Centro Universitario Regional Este; UruguayFil: Ruiz Diaz, Federico Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias. Instituto de Ictiología del Nordeste; ArgentinaFil: Alonso, Felipe. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Bio y Geociencias del NOA. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Museo de Ciencias Naturales. Instituto de Bio y Geociencias del NOA; ArgentinaFil: Bugeau, Horacio Baltazar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Aguilera, Gaston. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Mirande, Juan Marcos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentin

Morphological variability in populations of the fiddler crab Leptuca uruguayensis (Nobili, 1901) (Crustacea, Decapoda, Ocypodidae) from South America

Abstract A comparative study on size and shape of Leptuca uruguayensis was carried out between populations from Garças River, Brazil (BP), and Solís Grande River, Uruguay (UP). The size of the onset of sexual maturity was also estimated for UP. A total of 36 crabs BP and 387 crabs UP were analyzed. In the relative growth analysis, carapace width (CW) for both sexes, major cheliped length (LMC) for males and abdomen width (AW) for females were measured. The centroid size of carapace (1.40±0.19 cm BP and 1.88±0.30 cm UP) and cheliped (1.16±0.22 cm BP and 1.58±0.45 cm UP) differed significantly (p<0.001). The shape also differed significantly (p<0.001), having UP wider carapace than BP, rostrum projected forward and posterior margin positioned more anteriorly; the cheliped of UP was also wider than BP. In UP, males' CW ranged 4.28-19.5 mm and females' 2.53-16.3 mm CW; males' LMC ranged 1.79-31.60 mm and females' AW, 0.80-8.53 mm. The onset of sexual maturity of UP was estimated in 12.20 mm CW for males and 7.81 mm for females. These differences are likely related to abiotic variables acting distinctly in the two localities