Results 41 to 50 of about 209 (139)

DIVERSIDADE DE RAIAS DE ÁGUA DOCE (Chondrichthyes : Potamotrygonidae) NO ESTUÁRIO AMAZÔNICO

Arquivos de Ciências do Mar, 2008
Um levantamento sobre registros de ocorrência de raias de água doce (Potamotrygonidae) no estuário amazônico foi realizado utilizando-se dados  bibliográficos, informações de coleções científicas disponíveis on-line e amostragens de campo. Os resultados indicaram a presença de oito espécies nominais: Plesiotrygon iwamae, Paratrygon aiereba,Potamotrygon
Maurício Pinto De Almeida, Ronaldo Borges Barthem, Anderson da Silva Viana, Patrícia Charvet Almeida   +3 more
openaire   +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

Journal of Fish Biology, EarlyView.
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
Lucas E. P. Kampfert, João C. Maicrovicz, Daniel R. Blanco, Denise Lange, Carla S. Pavanelli, Heleno Brandão   +5 more
wiley   +1 more source

Occurrence of multiple congenital anomalies in Potamotrygon amandae (Elasmobranchii, Potamotrygoninae) embryos, including the first report of bicephaly

Journal of Fish Biology, EarlyView.
Abstract Reports of teratogenic embryos in elasmobranchs have been documented in multiple species, with proposed aetiologies including environmental disturbances, genetic mutations, predation, exposure to endocrine‐disrupting compounds and maternal stress.
Douglas de Castro Ribeiro, Raquel Lopes Queiroz, Cristiéle da Silva Ribeiro   +2 more
wiley   +1 more source

Phylogeography and conservation genetics of the Amazonian freshwater stingray Paratrygon aiereba Müller & Henle, 1841 (Chondrichthyes: Potamotrygonidae)

Neotropical Ichthyology
The family Potamotrygonidae is monophyletic comprising three genera: Paratrygon Duméril, Potamotrygon Garman and Plesiotrygon Rosa, Castello & Thorson.
Renata G. Frederico, Izeni P. Farias, Maria Lúcia Góes de Araújo, Patricia Charvet-Almeida, José A. Alves-Gomes   +4 more
doaj   +1 more source

Spatiotemporal eDNA Monitoring of Marine Biodiversity in a Hyperurbanised Coastal Environment

Environmental DNA, Volume 7, Issue 4, July–August 2025.
Using environmental DNA and a metabarcoding approach, we amplified and sequenced the cytochrome oxidase subunit I (COI) gene for invertebrates and the 16S rRNA gene for vertebrates. Our spatiotemporal analyses over a year and across four sites in Singapore revealed distinct communities between sites and timepoints for both the COI and 16S rRNA assays ...
Zhi Ting Yip, Zheng Bin Randolph Quek, Danwei Huang   +2 more
wiley   +1 more source

Serum chemistry, thyroxine concentration, and blood cell morphology of wild, young Blackchin Guitarfish Glaucostegus cemiculus sampled on the eastern Mediterranean coastline

Journal of Aquatic Animal Health, Volume 36, Issue 3, Page 281-299, September 2024.
Abstract Objective The Blackchin Guitarfish Glaucostegus cemiculus is endemic to the Mediterranean Sea and is critically endangered, but relevant routine laboratory data are unavailable. Our objectives were to determine the packed cell volume (PCV), comprehensive serum chemistry analytes, and serum total thyroxine (sTT4) concentration; compare serum ...
Nevo Schwartz, Danny Morick, Barak Azrieli, Aviad Scheinin, Dan Tchernov, Itamar Aroch   +5 more
wiley   +1 more source

The more stirring the better: cichlid fishes associate with foraging potamotrygonid rays

Neotropical Ichthyology
One hunting tactic of freshwater rays (Potamotrygonidae), termed "undulate the disc and stir substrate", is here reported to attract cichlids at two sites in the upper Paraná River.
Domingos Garrone-Neto, Ivan Sazima
doaj   +1 more source

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

Acta 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, Julia Bastos de Aquino, Luana Felix de Melo, Rosângela Felipe Rodrigues, Alan Peres Feraz de Melo, Maria Angélica Miglino, Rose Eli Grassi Rici   +6 more
doaj   +1 more source

Vulnerability of Eastern Tropical Pacific chondrichthyan fish to climate change

Global Change Biology, Volume 30, Issue 7, July 2024.
This assessment identifies sharks' vulnerability to climate change in a data‐poor tropical region and suggests management actions. Abstract Climate change is an environmental emergency threatening species and ecosystems globally. Oceans have absorbed about 90% of anthropogenic heat and 20%–30% of the carbon emissions, resulting in ocean warming ...
Florencia Cerutti‐Pereyra, Elizabeth J. Drenkard, Mario Espinoza, Brittany Finucci, Felipe Galván‐Magaña, Ana Hacohen‐Domené, Alexander Hearn, Mauricio E. Hoyos‐Padilla, James T. Ketchum, Paola A. Mejía‐Falla, Ana V. Moya‐Serrano, Andres F. Navia, Diana A. Pazmiño, Deni Ramírez‐Macías, Jodie L. Rummer, Pelayo Salinas‐de‐León, Oscar Sosa‐Nishizaki, Charles Stock, Andrew Chin   +18 more
wiley   +1 more source

SERUM COMPOSITION OF FRESHWATER STRINGRAYS (POTAMOTRYGONIDAE) ADAPTED TO FRESH AND DILUTE SEA WATER

The Biological Bulletin, 1973
1. Juvenile freshwater stingrays of the family Potamotrygonidae are unable to survive in salinities in excess of 20.6‰ when gradually acclimated.2. No differences were observed in blood pH or hematological parameters when fish adapted to a salinity of 14.5‰ were compared with freshwater controls.3. Significant increases were found in serum sodium (21%),
ROBERT W. GRIFFITH, PETER K. T. PANG, ANIL K. SRIVASTAVA, GRACE E. PICKFORD   +3 more
openaire   +2 more sources