Results 171 to 180 of about 3,578 (213)

Serial reversal learning in freshwater stingrays (Potamotrygon motoro)

Animal Cognition, 2019
Serial reversal learning is considered a reliable approach for the testing of behavioral flexibility, and animals that inhabit fluctuating habitats and different environments are expected to possess behavioral and cognitive flexibility. The ocellate river stingray (Potamotrygon motoro) is one such species.
Martha M. M. Daniel, Vera Schluessel
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Visual Pigment of the Freshwater Stingray, Paratrygon motoro

Nature, 1973
IN general the absorbance spectra of the visual pigments of deep-water and pelagic marine animals are blueshifted compared to those of coastal and estuarine animals, and the pigments of the latter are blueshifted compared with those of freshwater animals.
W R, Muntz, E, Church, H J, Dartnall
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PRESUMPTIVE DYSGERMINOMA IN AN ORANGE-SPOT FRESHWATER STINGRAY (POTAMOTRYGON MOTORO)

Journal of Zoo and Wildlife Medicine, 2015
A captive-born, 13-yr-old female orange-spot freshwater stingray, (Potamotrygon motoro), presented with an acute caudodorsal swelling. Ultrasonography revealed an intracoelomic mass of mixed echogenicity containing fluid pockets. The ray was euthanatized and gross postmortem examination confirmed the presence of a fluid-filled coelomic mass in the ...
Yousuf S, Jafarey, Ric A, Berlinski, Christopher S, Hanley, Michael M, Garner, Matti, Kiupel   +4 more
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Ultrastructure of spermiogenesis in a freshwater stingray, Himantura signifer

Ichthyological Research, 2005
Ultrastructural changes of spermatids during spermiogenesis in a freshwater stingray, Himantura signifer, are described. Differentiation of spermatids begins with modification of the nuclear envelope adjacent to the Golgi apparatus, before the attachment of the acrosomal vesicle.
Kannika Chatchavalvanich, Amara Thongpan, Masaaki Nakai   +2 more
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A hyaluronidase from Potamotrygon motoro (freshwater stingrays) venom: Isolation and characterization

Toxicon, 2008
Freshwater stingrays (Potamotrygon motoro) are known to cause human accidents through a sting located in its tail. In the State of Goiás, this accident happens especially during the fishing season of the Araguaia River. The P. motoro venom extracted from the sting presented hyaluronidase activity.
Marta R, Magalhães, Nelson Jorge, da Silva, Cirano J, Ulhoa   +2 more
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Metabolic organization of pregnant freshwater stingray and their offspring

Journal of Fish Biology
AbstractThe elucidation of energetic patterns in adult viviparous elasmobranchs and their offspring can contribute to understanding ecophysiological questions, such as maternal‐fetal metabolism and group life‐history traits. We characterized the energetic substrates in pregnant individuals and stages of offspring development in the freshwater stingray ...
Natalia Carvalho Fabricio da Silva, Bianca de Sousa Rangel, Évillyn dos Santos Zacheo, Douglas de Castro Ribeiro, Cristiéle da Silva Ribeiro   +4 more
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Environmentally-induced osmoregulation in Neotropical freshwater stingrays (Myliobatiformes: Potamotrygoninae) after controlling for phylogeny

Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 2021
The osmotic physiology of freshwater stingrays was investigated in fifteen species from white (WW), black (BW), and clearwater (CW) rivers of Brazilian hydrographic basins. Regardless of phylogeny, potamotrygonids collected in the BW (Negro, Jutai, Nhamunda, and Manacapuru rivers), and CW (Tapajos, Parana, Mutum, Demeni, and Branco rivers) exhibited ...
Wallice P, Duncan, Rubia N, Machado, Marisa N, Fernandes   +2 more
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Functional Morphology of the Gill in Amazonian Freshwater Stingrays (Chondrichthyes: Potamotrygonidae): Implications for Adaptation to Freshwater

Physiological and Biochemical Zoology, 2010
The gill morphologies of six species of potamotrygonid freshwater stingrays from the Amazon basin were investigated using light and electron microscopy. Some unique features were found in the potamotrygonid gill: (1) fingerlike protuberances on the gill filament, (2) an Alcian blue/periodic acid-Schiff-positive histochemical reaction for several cell ...
Wallice Paxiúba, Duncan, Oscar Tadeu Ferreira, da Costa, Marise Margareth, Sakuragui, Marisa Narciso, Fernandes   +3 more
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Neotropical freshwater stingrays (Chondrichthyes – Potamotrygoninae): biology, general features and envenomation

Toxin Reviews, 2019
Neotropical stingrays have stingers at the base of the tail, which are used in self-defense and are covered with an epithelium containing mucous and venom glands.
Juliana Luiza Varjão Lameiras, Oscar Tadeu Ferreira da Costa, Maria Cristina Dos-Santos   +2 more
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Societal perception, impacts and judgment values about invasive freshwater stingrays

Biological Invasions, 2019
We currently face a unique phase in the global biodiversity crisis because of massive introductions of non-native species into greatly altered ecosystems. These introductions frequently occur as a consequence of human constructions and structures such as dams that allow species to overcome historic established biogeographic barriers.
Daniel Alves dos Santos, Igor de Paiva Affonso, Hugo José Message, Edson Kyioshi Okada, Luiz Carlos Gomes, Hugo Bornatowski, Jean Ricardo Simões Vitule   +6 more
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