Results 11 to 20 of about 180 (97)

The evolutionary origin of the durophagous pelagic stingray ecomorph. [PDF]

Palaeontology, 2023
Abstract Studies of the origin of evolutionary novelties (novel traits, feeding modes, behaviours, ecological niches, etc.) have considered a number of taxa experimenting with new body plans, allowing them to occupy new habitats and exploit new trophic resources.
Marramà G, Villalobos-Segura E, Zorzin R, Kriwet J, Carnevale G.   +4 more
europepmc   +2 more sources

Testicular Morphology and Spermatogenesis in Potamotrygon motoro: Insights Into Reproduction of Freshwater Stingrays. [PDF]

J Morphol
Electron microscopy of Potamotrygon motoro spermatozoa. a – Illustration of a schematic sperm cell depicting the helical head, intermediate piece (midpiece), and flagellum. b ‐ Helical heads (Hh) of spermatozoa inserted into the cytoplasm of Sertoli cells (S) through openings in the plasma membrane. Scales: 10 μm.
Delgado MLR, Quirino PP, Gomes-Silva L, Dzyuba V, Dzyuba B, Ninhaus-Silveira A, Veríssimo-Silveira R.   +6 more
europepmc   +2 more sources

Branchial localization of acid (A-type) and base (B-type) excreting ionocytes in Amazonian stenohaline freshwater Potamotrygon ray. [PDF]

J Fish Biol
Abstract The branchial epithelium of Potamotrygon—a member of the only strictly freshwater elasmobranch family Potamotrygonidae—was observed via immunohistochemistry, and two distinct forms of ionocytes were identified. The acid (A‐type) and base (B‐type) secreting cells with respective basolateral–apical localizations of Na+/K+‐ATPase–Na+/H+ exchanger
Rossi MW, Wood CM, Val AL, Wilson JM.
europepmc   +2 more sources

Distribution modelling for Neotropical freshwater stingrays Potamotrygon brachyura and Potamotrygon motoro (Myliobatiformes, Potamotrygonidae) in the Uruguay River basin. [PDF]

J Fish Biol
Abstract This study aimed to identify geographical distribution patterns of the giant short‐tailed river stingray Potamotrygon brachyura and the motoro stingray Potamotrygon motoro in the Uruguay River basin. Data on presence/absence of stingrays were based on fishers' knowledge accessed by interviews through expeditions in Brazil, Argentina and ...
Pereira DAS, Reis RE, Fontoura NF.
europepmc   +2 more sources

Evolution of reproductive modes in sharks and rays

Journal of Evolutionary Biology, Volume 36, Issue 11, Page 1630-1640, November 2023., 2023
The evolution of reproductive modes in sharks, rays, and chimaeras. Abstract The ecological and life history drivers of the diversification of reproductive modes in early vertebrates are not fully understood. Sharks, rays and chimaeras (group Chondrichthyes) have an unusually diverse variety of reproductive modes and are thus an ideal group to test the
Gergely Katona, Flóra Szabó, Zsolt Végvári, Tamás Székely Jr, András Liker, Robert P. Freckleton, Balázs Vági, Tamás Székely   +7 more
wiley   +1 more source

Linking rivers, mixing faunas: How artificial connectivity between the Middle and Upper Paraná River basins shapes fish diversity in a tributary of the Itaipu Reservoir, Brazil. [PDF]

J Fish Biol
Abstract This work aimed to investigate the distribution and occurrence of fish species along the São Francisco Falso Braço Norte (SFFBN) River basin, a tributary of the Middle Paraná River basin now artificially connected to the Upper Paraná ecoregion, to evaluate how such connectivity may affect the biogeographic distribution and regional composition
Kampfert LEP, Maicrovicz JC, Blanco DR, Lange D, Pavanelli CS, Brandão H.   +5 more
europepmc   +2 more sources

Comparing the performance of 12S mitochondrial primers for fish environmental DNA across ecosystems

Environmental DNA, Volume 3, Issue 6, Page 1113-1127, November 2021., 2021
We propose a framework for comparing the performance of primer pairs, which we applied to the comparison of two fish eDNA primer pairs, teleo and MiFish‐U. We showed how those primer pairs could be best used together to increase diversity coverage of eDNA studies.
Andrea Polanco F., Eilísh Richards, Benjamin Flück, Alice Valentini, Florian Altermatt, Sébastien Brosse, Jean‐Claude Walser, David Eme, Virginie Marques, Stéphanie Manel, Camille Albouy, Tony Dejean, Loïc Pellissier   +12 more
wiley   +1 more source

Conservation threats and future prospects for the freshwater fishes of Ecuador: A hotspot of Neotropical fish diversity

Journal of Fish Biology, Volume 99, Issue 4, Page 1158-1189, October 2021., 2021
ABSTRACT Freshwater fish communities in Ecuador exhibit some of the highest levels of diversity and endemism in the Neotropics. Unfortunately, aquatic ecosystems in the country are under serious threat and conditions are deteriorating. In 2018–19, the government of Ecuador sponsored a series of workshops to examine the conservation status of Ecuador's ...
Windsor E. Aguirre, Gabriela Alvarez‐Mieles, Fernando Anaguano‐Yancha, Ricardo Burgos Morán, Roberto V. Cucalón, Daniel Escobar‐Camacho, Iván Jácome‐Negrete, Pedro Jiménez Prado, Enrique Laaz, Katherin Miranda‐Troya, Ronald Navarrete‐Amaya, Fredy Nugra Salazar, Willan Revelo, Juan F. Rivadeneira, Jonathan Valdiviezo Rivera, Edwin Zárate Hugo   +15 more
wiley   +1 more source

A test of the utility of DNA barcoding in the radiation of the freshwater stingray genus Potamotrygon (Potamotrygonidae, Myliobatiformes)

Genetics and Molecular Biology, 2008
DNA barcoding is a recently proposed global standard in taxonomy based on DNA sequences. The two main goals of DNA barcoding methodology are assignment of specimens to a species and discovery of new species.
Daniel Toffoli, Tomas Hrbek, Maria Lúcia Góes de Araújo, Maurício Pinto de Almeida, Patricia Charvet-Almeida, Izeni Pires Farias   +5 more
doaj   +1 more source

Two new species of freshwater stingrays of the genus Paratrygon (Chondrichthyes: Potamotrygonidae) from the Orinoco basin, with comments on the taxonomy of Paratrygon aiereba

Neotropical Ichthyology, 2021
The genus Paratrygon, currently recognized as the sole monotypic genus of the family Potamotrygonidae, has a considerably greater diversity than previously indicated, including molecular studies, which supported P.
Thiago Silva Loboda, Carlos A. Lasso, Ricardo de Souza Rosa, Marcelo Rodrigues de Carvalho   +3 more
doaj   +1 more source