Results 71 to 80 of about 873 (190)

A new species of freshwater stingray (Myliobatiformes: Potamotrygoninae) from northern South America

open access: yesNeotropical Ichthyology
A new species of freshwater stingray (Potamotrygoninae) is described from the Demerara River, Guyana and río Guanare, Venezuela. It is distinguished from all other regional congeneric taxa (i.e., Potamotrygon marinae, P. schroederi, P.
Devya Hemraj-Naraine   +5 more
doaj   +1 more source

Heterogeneidade de hemoglobina nos peixes da Amazonia [PDF]

open access: yesActa Amazonica, 1978
Resumo Os padrões eletroforáticos de hemoglobinas de peixes da Amazônia foram descritos. Os peixes incluíram a pirambóia sul-americana, Lepidosiren paradoxa, quatro espécies de raias de água doce do género Potamotrygon e teleósteos sctinopterígeos de 77 ...
Unni E. H. Fyhn   +5 more
doaj   +1 more source

Ecotoxicology of Potamotrygoninae freshwater stingrays: bioaccumulation, toxicological risks, and conservation implications

open access: yesFrontiers in Marine Science
Obligate freshwater stingrays of the Potamotrygoninae subfamily are endemic to South America and confined to freshwater systems heavily impacted by anthropogenic activities. These pressures often lead to habitat degradation, with unknown impacts on these
Neuciane Dias Barbosa   +9 more
doaj   +1 more source

Morphological aspects and germ cells of male reproductive tract of river stingray, Potamotrygon amandae

open access: yesActa Scientiarum: Biological Sciences, 2023
The family Potamotrygonidae are the only species of stingrays restricted to fresh water and located exclusively in South America. The objective of this research was to analyze the morphological aspects and germ cells of the male reproductive tract of ...
Stefhani Cristina Chan Jacik   +6 more
doaj   +1 more source

Fish distribution across altitudinal gradients in the Upper Paraguay River Basin: Implications for conservation in the Pantanal region

open access: yesConservation Science and Practice, Volume 7, Issue 7, July 2025.
This paper approaches the patterns in fish distribution across the altitudinal gradient in the Upper Paraguay River basin, from uplands to the floodplain. We compiled more than 75,000 available fish records and registered 342 fish species and your distribution along altitudinal gradient. Floodplain portion have higher species diversity than headwaters,
Adriana Maria Espinoza Fernando   +11 more
wiley   +1 more source

Gill dimensions in near-term embryos of Amazonian freshwater stingrays (Elasmobranchii: Potamotrygonidae) and their relationship to the lifestyle and habitat of neonatal pups

open access: yesNeotropical Ichthyology
This comparative study of gill morphometrics in near-term embryos of freshwater stingray potamotrygonids examines gill dimensions in relation to neonatal lifestyle and habitat.
Wallice Paxiúba Duncan   +2 more
doaj   +1 more source

Potamotrygon motoro

open access: yes
Potamotrygon motoro (Müller & Henle 1841) Distribution tropical S. A., east of Andes. Notes Barriga (1994), Galacatos et al. (2004), Valdiviezo-Rivera et al. (2018), Jácome-Negrete et al. (2018).
Escobar-Camacho, Daniel   +4 more
openaire   +2 more sources

Potamotrygon falkneri Castex, Maciel 1963

open access: yes, 2018
Published as part of Ota, Renata Rúbia, Deprá, Gabriel de Carvalho, Graça, Weferson Júnio da & Pavanelli, Carla Simone, 2018, Peixes da planície de inundação do alto rio Paraná e áreas adjacentes: revised, annotated and updated, pp. 1-111 in Neotropical Ichthyology 16 (2) on page 16, DOI: 10.1590/1982-0224-20170094, http://zenodo.org/record ...
Ota, Renata Rúbia   +3 more
openaire   +2 more sources

Potamotrygon wallacei Carvalho, Rosa & Araujo 2016

open access: yes, 2023
Potamotrygon wallacei Carvalho, Rosa & Araújo, 2016 Holotype: MZUSP 117809; adult female, 253 mm DW (cited as 264 mm DW in Carvalho et al., 2016), (Fig. 18); Rio Negro, municipality of Barcelos, Amazonas, Brazil, 0°57' 30.24"S, 62°56'14.697"W; depth: not listed; F. Marques et al.; 09 Jan 2011.
Lima, Arthur De   +4 more
openaire   +2 more sources

Morfometria de raias continentais (Chondrichthyes, Potamotrygonidae) do alto rio Paraná, Brasil = Morphometry of upper Paraná river freshwater stingrays (Chondrichthyes, Potamotrygonidae)

open access: yesActa Scientiarum: Biological Sciences, 2007
Potamotrygonidae constitui o único grupo recente de Chondrichthyes cujo habitat está restrito, exclusivamente, a águas continentais. Na planície de inundação do Alto rio Paraná, espécies desta família estabeleceram-se após o fechamento das comportas da ...
Antonio Guilherme Cândido da Silva   +1 more
doaj  

Home - About - Disclaimer - Privacy