RESUMO

Ecoregions and areas of endemism are central concepts in biogeography. Based on collection records and the Endemic Analyses implemented with NDM/VNDM method we analyzed fish areas of endemism in the junction of three freshwater ecoregions related to the Rio de la Plata estuary (Lower Parana, Lower Uruguay, Laguna dos Patos) in Southern Neotropical region. Using two grid cell sizes, results obtained showed the same general patterns. Areas of endemism recovered were mainly associated either to Lower Uruguay or to Laguna dos Patos. In both ecoregions nested areas of endemism were identified within larger patterns of endemism. Noteworthy, one area recovered occurred across Lower Uruguay and Laguna dos Patos limits. Our results also suggest a revision of the Lower Uruguay and Lower Parana ecoregion limits, and highlight the relevance of the Rio de la Plata estuary as a barrier and corridor for freshwater fishes in the area.(AU)

Las ecorregiones y áreas de endemismo son conceptos centrales en biogeografía. Basados en registros de colecciones y el análisis de endemismo implementado en NDM/VNDM, analizamos áreas de endemismo de peces en el sur de la región Neotropical, en la conjunción de tres ecorregiones de agua dulce relacionadas al estuario del Río de la Plata (Bajo Paraná, Bajo Uruguay, Laguna de los Patos). Usando dos tamaños de grilla, los resultados obtenidos mostraron los mismos patrones generales. Las áreas de endemismo obtenidas estuvieron principalmente asociadas tanto a la ecorregión Bajo Uruguay como a la Laguna de los Patos. En los dos casos, fueron identificadas áreas de endemismo anidadas dentro de los grandes patrones de endemismo. Además, se destacó un área que atravesó los límites de ambas ecorregiones. Nuestros resultados también sugieren que es necesaria una revisión de los límites entre Bajo Uruguay y Bajo Paraná y resaltan la relevancia del estuario del Río de la Plata como barrera y corredor para los peces de agua dulce de esta región.(AU)

Assuntos

RESUMO

Ecoregions and areas of endemism are central concepts in biogeography. Based on collection records and the Endemic Analyses implemented with NDM/VNDM method we analyzed fish areas of endemism in the junction of three freshwater ecoregions related to the Rio de la Plata estuary (Lower Parana, Lower Uruguay, Laguna dos Patos) in Southern Neotropical region. Using two grid cell sizes, results obtained showed the same general patterns. Areas of endemism recovered were mainly associated either to Lower Uruguay or to Laguna dos Patos. In both ecoregions nested areas of endemism were identified within larger patterns of endemism. Noteworthy, one area recovered occurred across Lower Uruguay and Laguna dos Patos limits. Our results also suggest a revision of the Lower Uruguay and Lower Parana ecoregion limits, and highlight the relevance of the Rio de la Plata estuary as a barrier and corridor for freshwater fishes in the area.(AU)

Las ecorregiones y áreas de endemismo son conceptos centrales en biogeografía. Basados en registros de colecciones y el análisis de endemismo implementado en NDM/VNDM, analizamos áreas de endemismo de peces en el sur de la región Neotropical, en la conjunción de tres ecorregiones de agua dulce relacionadas al estuario del Río de la Plata (Bajo Paraná, Bajo Uruguay, Laguna de los Patos). Usando dos tamaños de grilla, los resultados obtenidos mostraron los mismos patrones generales. Las áreas de endemismo obtenidas estuvieron principalmente asociadas tanto a la ecorregión Bajo Uruguay como a la Laguna de los Patos. En los dos casos, fueron identificadas áreas de endemismo anidadas dentro de los grandes patrones de endemismo. Además, se destacó un área que atravesó los límites de ambas ecorregiones. Nuestros resultados también sugieren que es necesaria una revisión de los límites entre Bajo Uruguay y Bajo Paraná y resaltan la relevancia del estuario del Río de la Plata como barrera y corredor para los peces de agua dulce de esta región.(AU)

Assuntos

RESUMO

Although the presence of apertural folds and lamellae is the most recognizable character of the Odontostomidae, some species lack them, mostly in Anctus Martens, 1860, Bahiensis Jousseaume, 1877 and Moricandia Pilsbry & Vanatta, 1898. Eudioptus avellanedae Doering, 1881 - a slender odontostomid species that lacks even the slightest trace of folds or lamellae in its shell aperture - was however transferred to Odontostomus by Pilsbry in 1902 on the basis of its building forward of the aperture-margins. It is currently placed in its own monotypic subgenus, Cyclodontina (Ventania) Parodiz, 1940, on the basis of about the same argument. In this paper we redescribe its shell morphology and, for the first time, describe the internal anatomy of the pallial complex and the reproductive and digestive systems. The presence of a spongy gland in the pallial complex; of a short penis sheath with no retractor muscle; of a bursa copulatrix duct longer than spermoviduct, and of an epiphallic gland strongly support the inclusion of this unusual species in Odontostomidae. The species is diagnosable by the sculpture of the protoconch, which is not smooth as previously described, but has waved axial ribs crossed by spiral lines in young specimens; the distinctive external and internal shape of the bursa copulatrix duct; the internal penis wall divided in three regions of different sculpture; the smooth inner wall of the vagina; the long and cylindrical epiphallus with a distal widening indicating the presence of an epiphallic gland, and the penis retractor muscle inserted in the distal end of a short flagellum. These characters support the validity of Ventania Parodiz, 1940, different from Cyclodontina Beck, 1837.

Assuntos

RESUMO

Although the presence of apertural folds and lamellae is the most recognizable character of the Odontostomidae, some species lack them, mostly in Anctus Martens, 1860, Bahiensis Jousseaume, 1877 and Moricandia Pilsbry & Vanatta, 1898. Eudioptus avellanedae Doering, 1881 - a slender odontostomid species that lacks even the slightest trace of folds or lamellae in its shell aperture - was however transferred to Odontostomus by Pilsbry in 1902 on the basis of its building forward of the aperture-margins. It is currently placed in its own monotypic subgenus, Cyclodontina (Ventania) Parodiz, 1940, on the basis of about the same argument. In this paper we redescribe its shell morphology and, for the first time, describe the internal anatomy of the pallial complex and the reproductive and digestive systems. The presence of a spongy gland in the pallial complex; of a short penis sheath with no retractor muscle; of a bursa copulatrix duct longer than spermoviduct, and of an epiphallic gland strongly support the inclusion of this unusual species in Odontostomidae. The species is diagnosable by the sculpture of the protoconch, which is not smooth as previously described, but has waved axial ribs crossed by spiral lines in young specimens; the distinctive external and internal shape of the bursa copulatrix duct; the internal penis wall divided in three regions of different sculpture; the smooth inner wall of the vagina; the long and cylindrical epiphallus with a distal widening indicating the presence of an epiphallic gland, and the penis retractor muscle inserted in the distal end of a short flagellum. These characters support the validity of Ventania Parodiz, 1940, different from Cyclodontina Beck, 1837.(AU)

Assuntos

RESUMO

The effect of forest exploitation on structure, diversity, and floristic composition of palmitodominated Atlantic forests at Misiones, Argentina. The effect of forest exploitation - timber and palmito (Euterpe edulis, Palmae) extraction -on structure, diversity, and floristic composition of forests known as palmitals of the Atlantic Forest of Argentina was analyzed. These palmitals are located in Misiones (54 °13’ W and 25°41´ S). Three 1 ha permanent plots were established: two in the "intangible" zone of the Iguazu National Park (PNI), and another in an exploited forest site bordering the PNI. Three 0.2 ha non-permanent plots were also measured. One was located in the PNI reserve zone where illegal palmito extraction occurs. The other two were in logged forest. All trees and palmitos with DBH> 10 cm were identified and DBH and height were measured. For each of the six sites, richness and diversity of tree species, floristic composition, number of endemic species, and density of harvestable tree species were estimated. The harvest of E. edulis increases density of other tree species, diminishing palmito density. Forest explotation (logging and palmito harvest) is accompanied by an increase in diversity and density of heliophilic species, which have greater timber value in the region. However, this explotation also diminishes the density of palmito, of endemic species which normally grow in low densities, and of species found on the IUCN Red List. Results suggest that forest structure may be managed for timber and palmito production. The "intangible" zone of the PNI has the greatest conservation value in the Atlantic Forest, since a greater number of endemisms and endangered species are found here. Rev. Biol. Trop. 56 (2): 721-738. Epub 2008 June 30.

Se analizó el efecto del aprovechamiento forestal (maderero y de la extracción de palmitos; Euterpe edulis, Palmae), sobre la estructura, diversidad y composición florística de los bosques denominados palmitales de la Selva Atlántica Argentina (54 °13’ W, 25°41´ S), en la provincia de Misiones, Argentina. Se establecieron 3 ha de parcelas permanentes, dos ubicadas en la zona intangible del Parque Nacional Iguazú (PNI) y otra en un sitio aprovechado forestalmente lindante. Se midieron tres parcelas no permanentes cada una de 0.2 ha. Una se ubicó en la zona de reserva del PNI donde hay extracciones ilegales de palmito. Las otras dos estaban en sitios con aprovechamiento forestal. Todos los árboles y palmitos DAP> 10 cm fueron identificados y se les midió DAP y altura. Para cada uno de los 6 sitios se estimó riqueza y diversidad de especies arbóreas, composición específica, número de especies endémicas y densidad de árboles de especies aprovechables forestalmente. La riqueza y diversidad de especies se correlacionó con la densidad de palmito. Los índices de Shannon de los sitios se compararon con la prueba t y la corrección de Bonferroni. Las estructuras diamétricas considerando todos lo árboles y solo las especies maderables se compararon con la prueba de Duncan. El aprovechamiento de E. edulis aumenta la densidad de otras especies arbóreas, disminuyendo la densidad de palmitos. El aprovechamiento forestal va acompañado de un aumento en la diversidad y en la densidad de especies heliofilas que son las que tienen mayor valor maderero en la región. Este aprovechamiento disminuye la densidad de palmitos, de especies endémicas que normalmente ocurren en bajas densidades y de especies que se encuentran en la lista roja de la UICN. Los resultados sugieren que se puede manejar la estructura del bosque para la producción de maderera y de palmito. La zona intangible del PNI es la que tiene mayor valor para la conservación de la Selva Atlántica ya que en él se encuentran mayor número de endemismos y las especies en peligro de extinción.

Assuntos

RESUMO

La insuficiente información sobre la flora, específicamente sobre la familia Orchidaceae y la inminente desaparición de los bosques en la Vertiente Oriental del río Chinchipe (San Ignacio, Cajamarca), fueron las razones suficientes que motivaron a realizar la presente investigación. La evaluación se realizó en cuatro localidades de la provincia San Ignacio (Cajamarca), durante el año 2000, con 27 cuadrantes de 500 m², distribuidos cada 100 m de altitud, desde los 800 hasta los 2700 m, el método de muestreo fue aleatorio. Según el índice de diversidad de ShannonWiener, la zona de estudio posee un alto grado de diversidad (entre H'= 5,93 en Selva Andina y H'= 4,02 en Camaná), gracias al buen estado de conservación de los bosques y a la topografía de la zona. Las localidades de Camaná-Crucero (173,55) son menos disímiles por presentar hábitats similares. Selva Andina (969,619) es la localidad más disímil con el grupo Crucero-Camaná-Nuevo Mundo, la cual a los 2700 m presenta un alto endemismo. Para las localidades evaluadas se reportan 205 especies distribuidas en 58 géneros, los cuales son reportes nuevos para la zona, 15 son registros nuevos para Perú, ocho de éstas dejan de ser endémicas para Ecuador. Se reporta por primera vez para Perú el género Chrysocycnis, y dos especies nuevas para la ciencia Sarcoglottis sp. y Maxillaria sp.

The insufficient information on the flora, specifically on the Orchidaceae family and the imminent destruction of the forests in the Eastern slope of the Chinchipe river (San Ignacio, Cajamarca), were the reasons that motivated to make the present investigation. The evaluation was carried out in four localities of the county San Ignacio (Cajamarca), during year 2000. Sampling was random with 27 quadrants an altitudinal range of 100 m and comprising an area of 500 m² each. Plots were distributed between 800 and 2700 m above sea level. According to the Shannon-Wiener Diversity Index diversity is high in the study area (> grade: Loc. Selva Andina: H' = 5,93 and

RESUMO

Biodiversity corridors comprise a mosaic of land uses connecting fragments of natural forest across a landscape. Two such corridors have been established along the eastern coast of Brazil: the Serra do Mar and the Central da Mata Atlântica corridors, along which most of the coastal plains are restinga areas. In this study, we analyze the present status of the endemic and endangered terrestrial vertebrates of both corridors. We sampled 10 restingas in both corridors, recording species of amphibians, reptiles, birds, and mammals. Some restingas harbor a relatively large number of endemic species, and two main regions of endemism can be identified along the restingas of both corridors: the coastal restingas from northern Espírito Santo State to southern Bahia State (between Linhares, ES, and Trancoso, BA), and the coastal region between the restingas of Maricá and Jurubatiba, Rio de Janeiro State. Six species of terrestrial vertebrates considered threatened with extinction are found in the restingas of Serra do Mar and Central da Mata Atlântica biodiversity corridors (Liolaemus lutzae, Formicivora littoralis, Mimus gilvus, Schistochlamys melanopis, and Trinomys eliasi). The region located between the restinga of Maricá and that of Jurubatiba is of special relevance for the conservation of vertebrate species of the restingas of the corridors because a considerable number of threatened species of terrestrial vertebrates are found there. We strongly recommend efforts to develop checklists of threatened faunas for the States of Espírito Santo and Bahia.

Corredores de biodiversidade compreendem um mosaico de usos do solo conectando fragmentos de vegetação natural ao longo da paisagem. Ao longo da costa leste do Brasil, dois corredores de biodiversidade foram estabelecidos: o da Serra do Mar e o Central da Mata Atlântica. A maioria das planícies costeiras ao longo desses dois corredores é constituída por restingas. Neste estudo analisamos o status atual das espécies de vertebrados terrestres endêmicas e ameaçadas nos dois corredores. Amostramos dez restingas nos dois corredores, registrando a ocorrência de espécies de anfíbios, répteis, aves e mamíferos. Algumas restingas apresentam número relativamente alto de espécies endêmicas e duas regiões principais de endemismos podem ser reconhecidas nas restingas ao longo dos corredores: as restingas costeiras do norte do Espírito Santo até o sul da Bahia (entre Linhares, ES, e Trancoso, BA) e a região costeira entre as restingas de Maricá e Jurubatiba, Estado do Rio de Janeiro. Seis espécies de vertebrados terrestres consideradas ameaçadas de extinção foram encontradas nas restingas dos corredores da Serra do Mar e Central da Mata Atlântica (Liolaemus lutzae, Formicivora littoralis, Mimus gilvus, Schistochlamys melanopis e Trinomys eliasi). A região localizada entre as restingas de Maricá e Jurubatiba é de especial relevância para a conservação de espécies de vertebrados das restingas nos corredores, pois nela foi encontrado elevado número de espécies ameaçadas. Recomendamos esforços para a elaboração de listas de fauna ameaçada para os Estados do Espírito Santo e Bahia.