80 documents found, page 1 of 8
Pervasive gaps in Amazonian ecological research
Carvalho, Raquel L.; Resende, Angelica F.; Barlow, Jos; França, Filipe M.; Moura, Mario R.; Maciel, Rafaella; Alves-Martins, Fernanda; Shutt, JackBiodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain underst...
Historical stability promoted higher functional specialization and originality ...
Rodrigues-Filho, Carlos A. S.; Leitão, Rafael P.; Zuanon, Jansen; Sánchez-Botero, Jorge I.; Baccaro, Fabricio B.Disturbances are events that influence the structure of biological assemblages, yet how historical disturbances have affected the functional structure of recent assemblages is still poorly known. We used species functional traits to investigate the effects of historical disturbances, such as past climate change (aridification), on the current structure of stream fish assemblages. Location: Amazon Basin and Braz...
Microhabitat segregation and fine ecomorphological dissimilarity between two cl...
Leitão, Rafael Pereira; Sánchez-Botero, Jorge Ivan; Kasper, Daniele; Cardoso, Victor Trivério; Araújo, Carolina Morais; Zuanon, JansenHabitat segregation is considered the mostprevalent resource-partitioning mechanism for streamfishes and the species morphology can be a strongpredictor of their spatial distribution. However, moststudies addressing morphology-habitat relationshipshave defined the space in physiognomically homoge-neous units (i.e., mesohabitat), probably not detectingsegregation among several closely related species. Herewe inv...
A multiple hypothesis approach to explain species richness patterns in neotropi...
Vieira, Thiago Bernardi; Pavanelli, Carla Simone; Casatti, Lilian; Smith, Welber Senteio; Benedito, Evanilde; Mazzoni, RosanaSeveral hypotheses are used to explain species richness patterns. Some of them (e.g. species-area, species-energy, environment-energy, water-energy, terrestrial primary productivity, environmental spatial heterogeneity, and climatic heterogeneity) are known to explain species richness patterns of terrestrial organisms, especially when they are combined. For aquatic organisms, however, it is unclear if these hyp...
Large-scale Degradation of the Tocantins-Araguaia River Basin
Pelicice, Fernando Mayer; Agostinho, Angelo Antonio; Akama, Alberto; Andrade Filho, José Dilermando; Azevedo-Santos, Valter M. [UNESP]Made available in DSpace on 2022-04-28T19:42:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-10-01; The Tocantins-Araguaia Basin is one of the largest river systems in South America, located entirely within Brazilian territory. In the last decades, capital-concentrating activities such as agribusiness, mining, and hydropower promoted extensive changes in land cover, hydrology, and environmental condit...
Cleaning interactions between shrimps (palaemonidae) and freshwater stingrays (...
Garrone-Neto, Domingos [UNESP]; Gadig, Otto Bismarck Fazzano [UNESP]; Zuanon, Jansen; Carvalho, Lucélia NobreMade available in DSpace on 2022-04-29T07:14:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-01-01; We report the first record of cleaning symbiosis between a river stingray, Potamotrygon falkneri, and a palaemonid shrimp, Macrobrachium jelskii. Shrimps of different sizes were observed cleaning adult stingrays partially buried in sandy substrate and shallow water, during the day in the Parana River, S...
Diet of two syntopic species of crenuchidae (Ostariophysi: Characiformes) in an...
Fernandes, Suzanne; Leitão, Rafael Pereira; Dary, Euriz?ngela Pereira; Guerreiro, Ana Isabel Camacho; Zuanon, Jansen; Bührnheim, Cristina MottaThis study assessed the diet of two poorly known syntopic fish species of the family Crenuchidae, Characidium aff. declivirostre and Leptocharacidium omospilus, in a Presidente Figueiredo’ rocky stream, Amazonas, Brazil. The stomach contents were analyzed and their Frequency of Occurrence (FO %) and Relative Volume (Vol %) were combined in a Feeding Index (IAi). We examined 20 individuals of C. aff. declivirost...
Hemiodus langeanii (Characiformes: Hemiodontidae), a new species from rio Amana...
Beltrão, Hélio Daniel; Zuanon, JansenHemiodus langeanii, new species, is described based on 20 specimens collected in the rio Amana, a tributary of rio Maués-Açú, rio Amazonas drainage, Brazil. The new taxon can be distinguished from its congeners by its high body (27.1-35.3%, average 32.3% SL vs. 18.8-28.5% in remaining species). The new species also exhibits a large lateral dark spot that is equal to, or greater than, the eye diameter (vs. small...
Remarkable geographic structuring of rheophilic fishes of the lower Araguaia River
Hrbek, Tomas; Meliciano, Natasha V.; Zuanon, Jansen; Farias, Izeni P.Rapids and waterfalls, and their associated fauna and flora are in peril. With the construction of each new hydroelectric dam, more rapids and waterfalls are destroyed, leading to the disappearance of associated fauna and flora. Areas of rapids harbor distinct, highly endemic rheophilic fauna and flora adapted to an extreme environment. Rheophilic habitats also have disjunct distribution both within and across ...
Reproductive and population parameters of discus fish symphysodon aequifasciatu...
Rossoni, Felipe; Amadio, Sidinéia Aparecida; Ferreira, Efrem J.G.; Zuanon, JansenThe ornamental discus fish Symphysodon aequifasciatus Pellegrin, 1904, is a popular endemic cichlid species from the Amazon basin, however scientific information concerning biology and ecology in its natural habitat is scarce despite its importance on the international aquarium trade. In this study we evaluated reproductive parameters of S. aequifasciatus in natural habitat in Piagaçu-Purus Sustainable Developm...