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1.
Wild animal genetic resource banking (GRB) represents a valuable tool in conservation breeding programs, particularly in cases involving endangered species such as the golden‐headed lion tamarin (Leontopithecus chrysomelas). Thus, we aimed to assess a sperm freezing protocol for golden‐headed lion tamarins using two different exenders: BotuBOV® (BB) and Test Yolk Buffer® (TYB). Ejaculates were collected by penile vibrostimulation from animals housed at São Paulo Zoological Park Foundation, São Paulo, Brazil, and after immediate analysis, two aliquots were diluted in BB and TYB. Postthawing samples were evaluated for total and progressive motility, plasma membrane and acrosome integrities, mitochondrial activity, susceptibility to oxidative stress, and sperm–egg‐binding. No differences between BB and TYB were found for most seminal parameters, except for acrosome integrity and susceptibility to oxidative stress (in both cases BB showed higher values). However, in spite of these differences and regardless of the extender used, postthaw sperm motility and viability with the described protocol were encouraging (on average >50% and >80%, respectively), indicating that sperm cryopreservation may be a short‐term measure for the conservation of golden‐headed lion tamarins.  相似文献   
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Cyclopid copepods collected mainly in aquatic microcosms and semiterrestrial habitats in the Juréia Ecological Reserve are studied. Hesperocyclops herbsti and Bryocyclops campaneri are described as new species and their taxonomical relationships discussed. Females of Muscocyclops operculatus (Chappuis) are redescribed and the males described for the first time. An emended diagnosis for Muscocyclops is proposed.  相似文献   
4.
The Oligochaeta of some streams flowing into the Rio de La Plata, Buenos Aires, Argentina, were investigated. Twenty nine taxa (twenty four naidids, five tubificids) were identified. Most species are cosmopolitan, but Dero evelinae, Pristina leidyi, Slavina isochaeta and Bothrioneurum sp. are neotropical. Bratislavia unidentata, Haemonais waldvogeli and Nais pardalis are reported for the first time in Argentina. Variants occurr in the shape of the distal end of the penial sheaths of Limnodrilus hoffmeisteri. The dominant Naidid genera are Dero and Pristina. In the polluted El Gato stream only L. hoffmeisteri and L. claparedeianus were found.  相似文献   
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The pollination biology and breeding systems ofKielmeyera coriacea andK. speciosa, two sympatric woody species common in the cerrado vegetation of C. Brazil, were studied. Both species have similar nectarless, polystemonous Papaver-type flowers which are visited by a similar spectrum of insects, though they bloom in different seasons and are thus phenologically isolated. Large carpenter bees seem to be the most important pollinators and these and other bees effect buzz pollen retrieval despite the fact that anthers are not poricidal. Both species ofKielmeyera possess strong xenogamous breeding systems. The presence of staminate flowers and andromonoecy inK. coriacea, as well as the longevity ofK. speciosa flowers are discussed as alternative strategies to improve pollination success and reproductive efficacy.  相似文献   
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Synopsis Extensive upstream migration of landlocked Arctic charr during spring floods was recorded in several tributaries of an oligotrophic lake in north-west Sweden. Migration was confined to a period of about two weeks and residence in most creeks was of short duration. Only fish migrating to two small productive lakes remained in the new habitat over the summer. Repeated annual migrations were only recorded in the creek leading to these lakes and no straying was observed among repeat migrants. Water temperatures provided the primary cues for initiation and direction of migration, although an ability to detect productive habitats by odour was indicated. Creek size, feeding opportunities during migration and conspeeific odour were subordinate guiding factors.  相似文献   
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Results of a 10-month study of the ecology and behavior of free- ranging woolly spider monkeys (Brachyteles arachnoides)in Brazil show that these animals are strongly folivorous. Leaf-eating accounted for more than 50% of the total feeding time in all samples but one and accounted for more than 80% of the total feeding time in three samples. Mature foliage was routinely eaten. Woolly spider monkeys consistently spend more than 50% of each day quietly resting and sleeping. Animals travel little except when actively feeding and show low levels of social interaction. Such an activity profile suggests that woolly spider monkeys may often be living near the limits of their energetic resources. The social organization of the species is unusual for a folivorous primate in that small groups of females and associated immature animals confine their activities to discrete home-range areas, whereas males are itinerant, traveling over the home ranges of various female groups. Animals sharing a common home-range area show no permanent daily pattern of association other than that of mother-dependent offspring. Foraging alone or with few conspecifics should maximize each individual’s returns from foraging by minimizing the day range that must be traveled each day to locate foods while simultaneously lowering interference competition for higher-quality dietary resources.  相似文献   
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Genetic diversity provides populations with the possibility to persist in ever-changing environments, where selective regimes change over time. Therefore, the long-term survival of a population may be affected by its level of genetic diversity. The Mexican howler monkey (Alouatta palliata mexicana) is a critically endangered primate restricted to southeast Mexico. Here, we evaluate the genetic diversity and population structure of this subspecies based on 83 individuals from 31 groups sampled across the distribution range of the subspecies, using 29 microsatellite loci. Our results revealed extremely low genetic diversity (HO = 0.21, HE = 0.29) compared to studies of other A. palliata populations and to other Alouatta species. Principal component analysis, a Bayesian clustering method, and analyses of molecular variance did not detect strong signatures of genetic differentiation among geographic populations of this subspecies. Although we detect small but significant FST values between populations, they can be explained by a pattern of isolation by distance. These results and the presence of unique alleles in different populations highlight the importance of implementing conservation efforts in multiple populations across the distribution range of A. p. mexicana to preserve its already low genetic diversity. This is especially important given current levels of population isolation due to the extreme habitat fragmentation across the distribution range of this primate.  相似文献   
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ABSTRACT White‐rumped Tanagers (Cypsnagra hirundinacea) are widely distributed in northern Brazil, Bolivia, and Paraguay, and are classified as vulnerable in the state of Paraná and as endangered in the state of São Paulo, Brazil. Little is currently known about their breeding biology. We studied the breeding behavior of White‐rumped Tanagers in the Cerrado (Neotropical savanna) in central Brazil from 2002 to 2007. The breeding period extended from mid‐August to mid‐December. Nests were cup‐shaped and located mainly in trees of the genus Kielmeyera at a mean height of 3.7 ± 0.3 m (SE). Clutch sizes varied from one to three eggs and the incubation period lasted an average of 16.0 ± 0.3 d. Incubation was by females only and started with the laying of the first egg. Mean nest attentiveness (percent time on nests by females) was 64 ± 0.08%. Nestlings were fed by males, females, and, when present, helpers. The mean rate of food delivery rate to nests was 5.2 ± 0.4 items/h, with rates similar for males (mean = 2.7 ± 0.3 items/h) and females (mean = 2.4 ± 0.3 items/h). The mean duration of the nestling period was 12.1 ± 0.5 d. Compared to many temperate species of tanagers, White‐rumped Tanagers in our study had relatively small clutches, low nest attentiveness, and long incubation periods. As with other tropical species, such characteristics might be due to food limitation or high rates of nest predation.  相似文献   
10.
The Neotropical region exhibits the greatest worldwide diversity and the diversification history of several clades is related to the puzzling geomorphologic and climatic history of this region. The freshwater Amazon ecoregion contains the main hydrographic basins of the Neotropical region that are highly dendritic and ecologically diverse. It contains a rich and endemic fish fauna, including one of its most iconic and economically important representatives, the bony-tongue Arapaima gigas (Teleostei, Osteoglossiformes). Here, we evaluated the projected distribution of the genus in different historical periods (Present, Last Glacial Maximum, Last Interglacial Maximum and Near Future) and interpreted these results in light of the genomic diversity and modeled historical demography. For that, we combined species distribution models, population genetic analysis using SNPs and deep learning model selection. We analyzed a representative sample of the genus from the two basins where it naturally occurs, four localities in the Amazon (Am) and three in the Tocantins-Araguaia (To-Ar) basin, as well as individuals from three fish farms. We inferred a potentially smaller distribution in the glacial period, with a possible refuge in central Am. Our genetic data agrees with this result, suggesting a higher level of genetic diversity in the Am basin, compared to that observed in To-Ar. Our deep learning model comparison indicated that the To-Ar basin was colonized by the population from the Am basin. Considering a global warming scenario in the near future, A. gigas could reach an even larger range, especially if anthropogenic related dispersal occurs, potentially invading new areas and impacting their communities.  相似文献   
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