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Pastore J.F.B.,State University of Feira de Santana | Cardoso D.B.O.S.,State University of Feira de Santana | Aymard C. G.A.,National Experimental University of the Western Plains
Novon | Year: 2010

A synopsis of the American genus Acanthocladus Klotzsch ex Hassk. (Polygalaceae), based primarily on herbarium studies, is presented, along with an identification key to the currently accepted eight species. Two new synonyms and the following new combinations are presented: A. dukei (Barringer) J. F. B. Pastore & D. B. O. S. Cardoso, A. pulcherrimus (Kuhlm.) J. F. B. Pastore & D. B. O. S. Cardoso, and A. santosii (Wurdack) J. F. B. Pastore & D. B. O. S. Cardoso. The names A. brasiliensis Klotzsch ex Hassk. and A. pulcherrimus are lectotypified. © 2010 Missouri Botanical Garden.


Milazzo M.L.,University of Texas Medical Branch | Cajimat M.N.B.,University of Texas Medical Branch | Duno G.,Ministerio de Sanidad y Asistencia Social | Duno F.,Ministerio de Sanidad y Asistencia Social | And 2 more authors.
Emerging Infectious Diseases | Year: 2011

Samples from rodents captured on a farm in Venezuela in February 1997 were tested for arenavirus, antibody against Guanarito virus (GTOV), and antibody against Pirital virus (PIRV). Thirty-one (48.4%) of 64 short-tailed cane mice (Zygodontomys brevicauda) were infected with GTOV, 1 Alston's cotton rat (Sigmodon alstoni) was infected with GTOV, and 36 (64.3%) of 56 other Alston's cotton rats were infected with PIRV. The results of analyses of field and laboratory data suggested that horizontal transmission is the dominant mode of GTOV transmission in Z. brevicauda mice and that vertical transmission is an important mode of PIRV transmission in S. alstoni rats. The results also suggested that bodily secretions and excretions from most GTOV-infected short-tailed cane mice and most PIRVinfected Alston's cotton rats may transmit the viruses to humans.


Collins S.M.,Cornell University | Bickford N.,University of Great Falls | Mcintyre P.B.,University of Wisconsin - Madison | Coulon A.,Cornell University | And 5 more authors.
Transactions of the American Fisheries Society | Year: 2013

Developing conservation strategies for migratory fishes requires an understanding of connectivity among populations. Neotropical rivers contain diverse and economically important assemblages of migratory fishes, but little is known about the population biology of most species. We examined the population structure of Prochilodus mariae, an abundant migratory fish species found in Venezuelan rivers that plays essential roles in both regional fisheries and ecosystem dynamics. By coupling otolith microchemistry and microsatellite genetic analyses, we were able to evaluate both natal origins of individual fish and genetic structure on a regional level. The chemistry of otolith cores inferred separate breeding grounds for four of six populations, with 75-85% of individuals from each river sharing a natal signature that is distinct from the other populations. In contrast, we detected no genetic structure, indicating that gene flow among these rivers prevents population differentiation. These disparate inferences underscore the complexity of conserving migratory species; otolith data suggest that ensuring fishery sustainability requires recognizing distinct breeding stocks, while gene flow reflects the importance of connectivity across the broader river network on an evolutionary time scale.We conclude that multiple methodological approaches may often be necessary to fully understand the spatial ecology and management needs of migratory fishes and, therefore, also influence local management practices. © American Fisheries Society 2013.


Hanson J.D.,Texas Tech University | Utrera A.,National Experimental University of the Western Plains | Fulhorst C.F.,University of Texas Medical Branch
Vector-Borne and Zoonotic Diseases | Year: 2011

Choclo virus (CHOV) and Maporal virus (MAPV) are enzootic in Panama and western Venezuela, respectively. The results of previous studies suggested that the fulvous pygmy rice rat (Oligoryzomys fulvescens) is the principal host of both viruses. The results of an analysis of nucleotide sequence data in this study indicated that the rodent associated with CHOV is the Costa Rican pygmy rice rat (Oligoryzomys costaricensis) and that the rodent associated with MAPV is the delicate pygmy rice rat (Oligoryzomys delicatus). As such, MAPV is ecologically distinct from CHOV and should be considered a species separate from CHOV. © Copyright 2011, Mary Ann Liebert, Inc.


Lasso C.A.,Institute Investigacion Of Recursos Biologicos Alexander Von Humboldt | Machado-Allison A.,Central University of Venezuela | Taphorn D.C.,National Experimental University of the Western Plains
Journal of Fish Biology | Year: 2016

About 1000 freshwater fishes have been found so far in the Orinoco River Basin of Venezuela and Colombia. This high ichthyological diversity reflects the wide range of landscapes and aquatic ecosystems included in the basin. Mountain streams descend from the high Andes to become rapid-flowing foothill rivers that burst out upon vast savannah flatlands where they slowly make their way to the sea. These white-water rivers are heavily laden with sediments from the geologically young Andes. Because their sediment deposits have formed the richest soils of the basin, they have attracted the highest density of human populations, along with the greatest levels of deforestation, wildfires, agricultural biocides and fertilizers, sewage and all the other impacts associated with urban centres, agriculture and cattle ranching. In the southern portion of the basin, human populations are much smaller, where often the only inhabitants are indigenous peoples. The ancient rocks and sands of the Guiana Shield yield clear and black water streams of very different quality. Here, sediment loads are miniscule, pH is very acid and fish biomass is only a fraction of that observed in the rich Andean tributaries to the north. For each region of the basin, the current state of knowledge about fish diversity is assessed, fish sampling density evaluated, the presence of endemic species and economically important species (for human consumption or ornamental purposes) described and gaps in knowledge are pointed out. Current trends in the fishery for human consumption are analysed, noting that stocks of many species are in steep decline, and that current fishing practices are not sustainable. Finally, the major impacts and threats faced by the fishes and aquatic ecosystems of the Orinoco River Basin are summarized, and the creation of bi-national commissions to promote standardized fishing laws in both countries is recommended. © 2016 The Fisheries Society of the British Isles


Lasso C.A.,Institute Investigacion Of Recursos Biologicos Alexander Von Humboldt Calle 28 A And 15 09 Bogota Colombia | Machado-Allison A.,Central University of Venezuela | Taphorn D.C.,National Experimental University of the Western Plains
Journal of Fish Biology | Year: 2016

About 1000 freshwater fishes have been found so far in the Orinoco River Basin of Venezuela and Colombia. This high ichthyological diversity reflects the wide range of landscapes and aquatic ecosystems included in the basin. Mountain streams descend from the high Andes to become rapid-flowing foothill rivers that burst out upon vast savannah flatlands where they slowly make their way to the sea. These white-water rivers are heavily laden with sediments from the geologically young Andes. Because their sediment deposits have formed the richest soils of the basin, they have attracted the highest density of human populations, along with the greatest levels of deforestation, wildfires, agricultural biocides and fertilizers, sewage and all the other impacts associated with urban centres, agriculture and cattle ranching. In the southern portion of the basin, human populations are much smaller, where often the only inhabitants are indigenous peoples. The ancient rocks and sands of the Guiana Shield yield clear and black water streams of very different quality. Here, sediment loads are miniscule, pH is very acid and fish biomass is only a fraction of that observed in the rich Andean tributaries to the north. For each region of the basin, the current state of knowledge about fish diversity is assessed, fish sampling density evaluated, the presence of endemic species and economically important species (for human consumption or ornamental purposes) described and gaps in knowledge are pointed out. Current trends in the fishery for human consumption are analysed, noting that stocks of many species are in steep decline, and that current fishing practices are not sustainable. Finally, the major impacts and threats faced by the fishes and aquatic ecosystems of the Orinoco River Basin are summarized, and the creation of bi-national commissions to promote standardized fishing laws in both countries is recommended. © 2016 The Fisheries Society of the British Isles.


PubMed | Institute Investigacion Of Recursos Biologicos Alexander Von Humboldt, Central University of Venezuela and National Experimental University of the Western Plains
Type: Journal Article | Journal: Journal of fish biology | Year: 2016

About 1000 freshwater fishes have been found so far in the Orinoco River Basin of Venezuela and Colombia. This high ichthyological diversity reflects the wide range of landscapes and aquatic ecosystems included in the basin. Mountain streams descend from the high Andes to become rapid-flowing foothill rivers that burst out upon vast savannah flatlands where they slowly make their way to the sea. These white-water rivers are heavily laden with sediments from the geologically young Andes. Because their sediment deposits have formed the richest soils of the basin, they have attracted the highest density of human populations, along with the greatest levels of deforestation, wildfires, agricultural biocides and fertilizers, sewage and all the other impacts associated with urban centres, agriculture and cattle ranching. In the southern portion of the basin, human populations are much smaller, where often the only inhabitants are indigenous peoples. The ancient rocks and sands of the Guiana Shield yield clear and black water streams of very different quality. Here, sediment loads are miniscule, pH is very acid and fish biomass is only a fraction of that observed in the rich Andean tributaries to the north. For each region of the basin, the current state of knowledge about fish diversity is assessed, fish sampling density evaluated, the presence of endemic species and economically important species (for human consumption or ornamental purposes) described and gaps in knowledge are pointed out. Current trends in the fishery for human consumption are analysed, noting that stocks of many species are in steep decline, and that current fishing practices are not sustainable. Finally, the major impacts and threats faced by the fishes and aquatic ecosystems of the Orinoco River Basin are summarized, and the creation of bi-national commissions to promote standardized fishing laws in both countries is recommended.


Perez A.,National Experimental University of the Western Plains | Fabre N.N.,Federal University of Alagoas
Journal of Fish Biology | Year: 2013

Using geometric morphometrics, the skull and otolith of tiger catfish Pseudoplatystoma metaense were analysed to identify population structure in tributaries of the Apure River (i.e. the Sarare, Caparo, Guanare, Portuguesa and San Carlos Rivers) in the Orinoco basin, Venezuela. The analyses show uniformity in skull and otolith shapes of P. metaense within and among four tributaries, with only the Caparo River showing significant differences. Within the Apure basin, the stock of P. metaense was differentiated through spawning, refuge and nursery areas. This study concludes that populations of P. metaense from each major tributary in the Orinoco basin should be considered as part of a metapopulation system for management purposes. Human disturbances in the catchment have directly reduced the spawning areas available to this species, decreased the total biomass and changed the spatial distribution of spawning areas. © 2013 The Authors. Journal of Fish Biology © 2013 The Fisheries Society of the British Isles.


Dorr L.J.,Smithsonian Institution | Stergios B.,National Experimental University of the Western Plains
PhytoKeys | Year: 2014

Four new species of Pilea (Urticaceae) from the Andes of Venezuela are described and illustrated: Pilea matthewii sp. nov., P. miguelii sp. nov., P. nicholasii sp. nov., and P. nidiae sp. nov. The affinities of these species and their positions within the informal classifications of Pilea proposed by Weddell and Killip are discussed. Notes on other species of Pilea found in Venezuela also are presented. © Laurence J. Dorr, Basil Stergios.


Perez-Lozano A.,National Experimental University of the Western Plains | Aniello B.,Instituto Nacional Of Investigaciones Agricolas
Latin American Journal of Aquatic Research | Year: 2013

Population parameters, performance index (∅) and exploitation rates (E = F/Z), of the 14 most important commercial fish species, in the Apure River, were estimated from length frequency distributions of commercial catches in the period 2000-2003. Growth parameters were used to determine the status of the principal fisheries resources of the Apure River. The analyzed species represented 83% of the total commercial species. The results showed a predominance of values relativity low of K and high L∞, common in longevity species. This data combined with the high values from estimations of Z and F showed a survival annual high rate and low stock tuner-over rate. The E estimations for the 14 fish species were high. E0,1 (0.50- 0.94). The overfishing indicators to four most fish species abundant (P. mariae P. tigrinum, M. duriventre y H. littorale), showed that at least three species were heavy exploited. In general the analysis indicate that these 14 fish species have been strongly fished, and the data obtained is a starting point (as biological reference point) to be used for the assessment and management of fisheries resources in the Apure River.

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