Results 21 to 30 of about 889 (175)

Records of new localities and hosts for crustacean parasites in fish from the eastern Amazon in northern Brazil. [PDF]

J Parasit Dis, 2017
The aim of this study was to investigate parasites crustacean fauna in Arapaima gigas, Cichla monoculus, Cichla ocellaris, Cichla jariina, Satanoperca jurupari, Leporinus friderici, Leporinus fasciatus, Hoplias malabaricus, Phractocephalus hemioliopterus,
Oliveira MSB, Corrêa LL, Oliveira Ferreira D, Neves LR, Tavares-Dias M.   +4 more
europepmc   +3 more sources

Hábitos alimentares e sobreposição trófica das raias Potamotrygon falkneri e Potamotrygon motoro (Chondrichthyes, Potamotrygonidae) na planície alagável do alto rio Paraná, Brasil = Feeding habitats and trophic overlap of the freshwater stingrays Potamotrygon falkneri e Potamotrygon motoro (Chondrichthyes, Potamotrygonidae) in the upper Paraná river floodplain, Brazil

Acta Scientiarum: Biological Sciences, 2006
As raias Potamotrygon falkneri e Potamotrygon motoro foram avaliadas em relação à composição de suas dietas e a sobreposição do nicho trófico nos períodos de seca (agosto/2004) e cheia (janeiro/2005) na planície alagável do alto rio Paraná, em três ...
Milza Celi Fedatto Abelha, Alessandra Pasian Lonardoni, Erivelto Goulart, Edson Fontes de Oliveira   +3 more
doaj   +1 more source

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

Record of the freshwater stingrays Potamotrygon brachyura and P. motoro (Chondrichthyes, Potamotrygonidae) in the lower Uruguay river, South America Registro das raias de água doce Potamotrygon brachyura e P. motoro (Potamotrygonidae) no baixo rio Uruguai, America do Sul

Acta Amazonica, 2012
Freshwater stingrays, or potamotrygonids, are restricted to Neotropical river drainages. These elasmobranchs are well adapted to freshwater environments and the number of described species gradually increases as further research is carried out.
María Cristina Oddone, Gonzalo Velasco, Patricia Charvet   +2 more
doaj   +2 more sources

Complete mitochondrial genome of the ocellate river stingray (Potamotrygon motoro) [PDF]

Mitochondrial DNA, 2014
We determined the first complete mitochondrial genome sequence of Potamotrygon motoro from South American freshwater stingrays. The total length of P. motoro mitogenome is 17,448 bp, which consists of 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and a control region, with the genome organization and gene order being identical to that of the ...
Hong-Mei, Song, Xi-Dong, Mu, Min-Xia, Wei, Xue-Jie, Wang, Jian-Ren, Luo, Yin-Chang, Hu   +5 more
  +8 more sources

A comparison of staff presence and signage on zoo visitor behavior

Zoo Biology, Volume 42, Issue 3, Page 407-415, May/June 2023., 2023
The presence of uniformed zoo staff reduced negative behaviors by zoo visitors more effectively than signage. Abstract Many zoos favor the use of signage to encourage learning and positive visitor experiences as well as discourage negative behaviors by visitors because of its simplicity, relatively low maintenance needed, and low cost. However, current
Claudia Tay, Todd J. McWhorter, Shangzhe Xie, Tiara Sophia Binte Mohd Nasir, Borja Reh, Eduardo J. Fernandez   +5 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

Combined effects of life‐history traits and human impact on extinction risk of freshwater megafauna

Conservation Biology, Volume 35, Issue 2, Page 643-653, April 2021., 2021
Abstract Megafauna species are intrinsically vulnerable to human impact. Freshwater megafauna (i.e., freshwater animals ≥30 kg, including fishes, mammals, reptiles, and amphibians) are subject to intensive and increasing threats. Thirty‐four species are listed as critically endangered on the International Union for Conservation of Nature (IUCN).
Fengzhi He, Simone D. Langhans, Christiane Zarfl, Roland Wanke, Klement Tockner, Sonja C. Jähnig   +5 more
wiley   +1 more source

Electroreception in the obligate freshwater stingray, Potamotrygon motoro [PDF]

Marine and Freshwater Research, 2015
Elasmobranch fishes use electroreception to detect electric fields in the environment, particularly minute bioelectric fields of potential prey. A single family of obligate freshwater stingrays, Potamotrygonidae, endemic to the Amazon River, demonstrates morphological adaptations of their electrosensory system due to characteristics of a high impedance
Lindsay L. Harris, Christine N. Bedore, Stephen M. Kajiura   +2 more
openaire   +1 more source

Mitochondrial DNA suggests Hybridization in Freshwater Stingrays Potamotrygon (POTAMOTRYGONIDAE: MYLIOBATIFORMES) from the Xingu river, Amazonia and reveals speciation in Paratrygon aireba

Anais da Academia Brasileira de Ciências, 2021
In the Xingu river basin, Brazil, occurs two genera of Potamotrygonidae family: Potamotrygon and Paratrygon. In this region, the taxa have significant economic importance for the ornamental fishing industry, being intensively captured, especially the ...
DAMIRES SANCHES, THAIS MARTINS, ÍTALO LUTZ, IVANA VENEZA, RAIMUNDO DA SILVA, FELIPE ARAÚJO, JANICE MURIEL-CUNHA, IRACILDA SAMPAIO, MAGALI GARCIA, LEANDRO SOUSA, GRAZIELLE EVANGELISTA-GOMES   +10 more
doaj   +1 more source