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91.
The first step to understanding the species present in a particular area is to perform inventory and assemblage studies. To obtain a species inventory, it is important to determine parameters such as species richness and relative abundance. This information can be useful for future studies and decision-making purposes in the conservation area. Despite the fundamental role of the terrestrial Heteroptera in ecosystems, they remain poorly known. We expected that the terrestrial Heteroptera species assemblage would be strongly associated with plant communities. Presently, 840 samples were collected in northern Argentine Patagonia during two years, 2013 and 2014. A total of 1950 adults of terrestrial Heteroptera belonging to 12 families, 32 species, and 8 morphospecies were found. Various statistical techniques were applied to correct the observed data for undersampling bias. These suggested that the lower boundary of the summer Heteroptera species richness in northern Patagonia was about 44–54 species. We concluded that the high regional habitat heterogeneity along the west-to-east and south-to-north gradients was paralleled by the turnover of Heteroptera. However, the Patagonian steppe shared a high number of species with the Monte and Subantarctic provinces. The suction sampling technique is an efficient technique to collect Heteroptera in environments with different plant structure and should thus be used in a complementary way with the sweeping technique.  相似文献   
92.
Male and female European Robins Erithacus rubecula display their red breasts in year‐round territorial contests. Despite the clear signalling role of the red breast, little is known about its sexual dimorphism or trends in size when Robins age. We studied these patterns in resident and migrant Robins in a Mediterranean population. Both male and female first‐year Robins had smaller red breasts than second‐year individuals. Females, but not males, showed a reduction in badge area after the second year of life, leading to sexual dimorphism in red breast area in the oldest Robins. The grey fringe around the red breast showed a steady increase in width in males when ageing, but not in females, also leading to sexual dimorphism in this trait among oldest Robins. The contrast between the red breast and its surrounding grey fringe was higher than that between the breast and the back at both high and low environmental light intensities. This suggests that the grey fringe could function as a frame to highlight the perimeter of the red breast, and that the Robin’s plumage is equally suited to display in open areas and forest understoreys. Our study suggests that the extent of the red breast and its grey frame could confer information about the age and sex of the birds, and thus be used as a signal in territorial contests and mating decisions.  相似文献   
93.
ABSTRACT. The species richness and quantity of naked amebae were determined in the bulk soil and rhizoplane of the desert plant Escontria chiotilla in the Valley of Tehuacan, Mexico. Samples from bulk soil were taken at 10-cm and 30-cm depths in April, May and July, 1993, and from roots and soil at a 10-cm depth in June and July, 1994. Quantity of amebae obtained by Most Probable Number method increased in the rhizoplane by two orders of magnitude after rains. Likewise, the countable population of amebae doubled in numbers at both the 10- and 30-cm depths after rains. We isolated 163 strains from both root and soil environments, which were grouped into 40 bactivorous and/or generalist species belonging to 19 genera. Species richness showed no clear dominance of a particular genus in either bulk soil or root. Acanthamoeba (groups II and III, Pussard & Pons) and Vahlkampfia accounted for 12.5% and 15% of the total number of species, respectively. However, greater species richness was found in bulk soil than on root surfaces. We concluded that the diversity of naked amebae, taken as numbers of individuals (or as biomass) of each species and its evenness, is still needed to assess the ecological roles of Acanthamoeba and Vahlkampfia in the soil environment.  相似文献   
94.
Summary

The development and improvement of artificial incubation techniques for freshwater crayfish eggs and their incorporation into the working schedule of breeding centres is of great interest for commercial production. Factors such as the water circulation system, flow rate, thermal treatment, etc., could strongly influence the success of the process. The present study attempts to test the possible influence of one of these variables, the thermal regime, on both the duration of embryonic development and the efficiency rates obtained in the artificial incubation of white-clawed crayfish (Austropotamobius pallipes) eggs. Four different thermal treatments were tested (three of them included a period at low temperature: 4°-5°C). Survival rates to juvenile stage 2 were similar in the four cases, ranging between 66.7 and 72.7%. We conclude that water cooling (an expensive management procedure) is not necessary in astacid breeding centres provided that egg development takes place at moderately low temperatures (8°-10°C) with a subsequent increase of up to 15°C from the eyed stage. However, the inclusion of periods at low temperature (4°-5°C) allows the staggered production of juvenile batches throughout a 3-week period without adverse effects on efficiency rates. This could be useful to breeding centres in meeting seasonal market requirements. In our study, egg and juvenile losses (mortality rate: 15–20%) were concentrated during the last phases of embryogenesis, particularly from the eyed stage to juvenile stage 2, during which they amounted to more than 90% of the overall mortality which took place during the artificial incubation process.  相似文献   
95.
This study was conducted to assess the reliability of computed tomography (CT) for diagnosing bot fly infestations by Cephenemyia stimulator (Clark) (Diptera: Oestridae) in roe deer (Capreolus capreolus L.) (Artiodactyla: Cervidae). For this purpose, the heads of 30 animals were analysed, firstly by CT and then by necropsy, which was used as the reference standard method. The prevalence values obtained by both methods were identical; the prevalence of infestation was 40.0% overall, and was higher in males (45.5%) than in females (25.0%). These results highlight the usefulness of CT as an alternative or non‐invasive method for diagnosing cephenemyiosis in live‐captured roe deer and in hunting trophies or museum collections that cannot be destroyed or damaged.  相似文献   
96.
Najash rionegrina Apesteguía & Zaher, 2006 , a terrestrial fossil snake from the Upper Cretaceous of Argentina, represents the first known snake with a sacrum associated with robust, well‐developed hind limbs. Najash rionegrina documents an important gap in the evolutionary development towards limblessness, because its phylogenetic affinities suggest that it is the sister group of all modern snakes, including the limbed Tethyan snakes Pachyrhachis, Haasiophis, and Eupodophis. The latter three limbed marine fossil snakes are shown to be more derived morphologically, because they lack a sacrum, but have articulated lymphapophyses, and their appendicular skeleton is enclosed by the rib cage, as in modern snakes.  相似文献   
97.
Abstract: Since 1997 the Mexican government has promoted Management Units for Conservation and Sustainable Use of Wildlife (UMAs) on private and community lands as an economically attractive mean for the conservation of biodiversity. To date, compliance of UMAs with stated sustainability goals has not been evaluated. Thus, we designed multicriteria evaluation framework based on the stated objectives of the national UMA program and applied it to a sample of 6 UMAs operating in peasant communities near or in the Calakmul Biosphere Reserve in Campeche, Mexico. Evaluation criteria covered thematic areas of environment, economy, social development, and laws and rules. We formulated 15 criteria with 29 indicators, and 133 verifiers. Data for the verifiers were based on direct observation, interviews with key actors in the peasant communities, participation in regional meetings, scrutiny of government reports, and databases. We calculated sustainability indexes by weighting, summing, and standardizing verifiers to percentage scales, and aggregating to the successive higher hierarchical levels of the evaluation framework. We found an average overall sustainability index of 45.7% for the UMAs evaluated. Scores were highest for the environment thematic area (55.2%), followed by economy (43.4%), social development (42.3%), and laws and rules (41.7%). We observed particularly low indicators for management strategies, habitat monitoring, environmental education, and knowledge of wildlife laws. We conclude that the contribution of UMAs to the conservation and sustainable use of biodiversity could be improved by a number of actions. These include developing wildlife management educational programs with a strong environmental legislation component, the correct enforcement of wildlife laws, and creating country-wise links among academic and governmental institutions promoting the work with regional and national wildlife experts.  相似文献   
98.
Fabry disease (FD) is a lysosomal storage disorder, which develops due to a deficiency in the hydrolytic enzyme, α-galactosidase A (α-Gal A). Alpha-Gal A hydrolyzes glycosphingolipid globotriaosylceramide (Gb3), and an α-Gal A deficiency leads to Gb3 accumulation in tissues and cells in the body. This pathology is likely to involve multiple systems, but it is generally considered to affect primarily vascular endothelium. In this study, we investigated mutations in the GLA gene, which encodes α-Gal A, in Mexican families with FD. We included seven probands with FD that carried known mutations. We analysed pedigrees of the probands, and performed molecular screening in 65 relatives with the potential of carrying a GLA mutation. Five mutations (P40S, IVS4 +4, G328V, R363H, R404del) were detected in seven unrelated Mexican families with the classic FD phenotype. Of the 65 relatives examined, 42 (64.6%) had a GLA gene mutation. In summary, among seven Mexican probands with FD, 65 relatives were at risk of carrying a known GLA mutation, and molecular screening identified 42 individuals with the mutation. Thus, our findings showed that it is important to perform molecular analysis in families with FD to detect mutations and to provide accurate diagnoses for individuals that could be affected.  相似文献   
99.
The male call of Capnioneura mitis, produced by drumming, is recorded and analyzed for the first time. It also represents the first known signal for the genus. It consists of a highly variable number of beats (2–32) with inter‐beat duration approximately constant along the call, but inter‐beat duration is temperature dependent. Thus, at 13°C the mean inter‐beat duration is 1.397 s (SD = 0.050) while at 21°C it is 1.139 s (SD = 0.093). The call pattern exhibited by this species, as those of the majority of previously studied Capniidae species, can be catalogued as an ancestral or near‐ancestral percussive monophasic signal.  相似文献   
100.
In orchid bees, males signal their availability as mates by fanning ‘perfumes’, i.e. blends of volatiles that are collected from environmental sources and stored in hind leg pouches. The chemical composition of such perfumes in males with either two or three mandibular teeth has previously led to the discovery of two sympatric, cryptic lineages within Euglossa viridissima Friese on the Yucatan peninsula, Mexico. Here, we combine chemical, morphological, and genetic data for an integrated characterization of the two lineages. The lectotype of E. viridissima Friese in the Museum of Natural History in Vienna has two mandibular teeth, and the species name viridissima must thus be assigned to the predominantly bidentate lineage, whereas the completely tridentate lineage is described as a novel species, Euglossa dilemma sp. nov. Bembé & Eltz. Chemical profiling and microsatellite genotyping revealed that E. viridissima males can occasionally (~10% of individuals) express a third mandibular tooth, but this tooth is not positioned centrally on the mandible as in E. dilemma, but is displaced towards the tip. Thus, males of the two lineages can be unambiguously diagnosed by mandibular characters alone. Based on 889 bp of CO1 sequence data, we confirm that E. viridissima and E. dilemma constitute a monophyletic group within the genus Euglossa. However, CO1 alone failed to separate these two lineages due to the lack of parsimony‐informative sites. Both species occur in broad sympatry across Central America, but the orchid bees recently introduced to Florida have three mandibular teeth in males, i.e. belong to E. dilemma. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 163 , 1064–1076.  相似文献   
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