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91.
Juan Rull Solana Abraham Adalecio Kovaleski Diego F. Segura Mariana Mendoza M. Clara Liendo M. Teresa Vera 《Entomologia Experimentalis et Applicata》2013,148(3):213-222
Tropical tephritids are ideally suited for studies on population divergence and speciation because they include species groups undergoing rapid radiation, in which morphologically cryptic species and sister species are abundant. The fraterculus species group in the Neotropical genus Anastrepha is a case in point, as it is composed of a complex of up to seven A. fraterculus morphotypes proposed to be cryptic species. Here, we document pre‐ and post‐zygotic barriers to gene flow among adults of the Mexican A. fraterculus morphotype and three populations (Argentina, Brazil, and Peru) belonging to two separate morphotypes (Brazilian 1 and Peruvian). We unveiled three forms of pre‐zygotic reproductive isolation resulting in strong assortative mating. In field cages, free‐ranging male and female A. fraterculus displayed a strong tendency to form couples with members of the opposite sex belonging to their own morphotype, suggesting that male pheromone emission, courtship displays, or both intervene in shaping female choice before actual contact and coupling. In addition, males and females of the Peruvian morphotype became receptive and mated significantly later than adults of the Mexican and Brazilian 1 morphotypes. After contact, Mexican females exhibited greater mating discrimination than males when facing adults of the opposite sex belonging to either the Peruvian or the Brazilian 1 morphotype as evidenced by vigorous resistance to penetration once they had been forcefully mounted by heterotypic males. Forced copulations resulted in production of F1 hybrids that were either less viable (and partially fertile) than parental crosses or even sterile. Our results suggest that the Mexican morphotype is a distinct biological entity and that pre‐zygotic reproductive isolation through divergence in courtship or male‐produced pheromone and other mechanisms appear to evolve faster than post‐zygotic isolation in the fraterculus species group. 相似文献
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Diana Katherine Ortega-González Diego Zaragoza José Aguirre-Garrido Hugo Ramírez-Saad César Hernández-Rodríguez Janet Jan-Roblero 《Folia microbiologica》2013,58(6):569-577
Increasing contamination of soil and groundwater with benzene, toluene, and xylene (BTX) due to activities of the chemical and oil refinery industry has caused serious environmental damage. Efficient methods are required to isolate and degrade them. Microorganisms associated with rhizosphere soil are considered efficient agents to remediate hydrocarbon contamination. In this study, we obtained a stabilized bacterial consortium from the rhizosphere soil of Cyperus sp. grown in a petroleum-contaminated field in Southern Mexico. This consortium was able to completely degrade BTX in 14 days. Bacteria isolated from the consortium were identified by 16S rRNA gene sequence analysis as Ralstonia insidiosa, Cellulomonas hominis, Burkholderia kururiensis, and Serratia marcescens. The BTX-degradation capacity of the bacterial consortium was confirmed by the detection of genes pheA, todC1, and xylM, which encoded phenol hydroxylase, toluene 1,2-dioxygenase, and xylene monooxygenase, respectively. Our results demonstrate feasibility of BTX biodegradation by indigenous bacteria that might be used for soil remediation in Southern Mexico. 相似文献
94.
Diego Pavón‐Jordán Patrik Karell Kari Ahola Heikki Kolunen Hannu Pietiäinen Teuvo Karstinen Jon E. Brommer 《Ibis》2013,155(4):823-834
Understanding how survival is affected by the environment is essential to gain insight into population dynamics and the evolution of life‐history traits as well as to identify environmental selection pressures. However, we still have little understanding of the relative effect of different environmental factors and their interactions on demographic traits and population dynamics. Here we used two long‐term, individual‐based datasets on Tawny Owl Strix aluco (1981–2010) and Ural Owl S. uralensis (1986–2010) to undertake capture‐mark‐recapture analysis of annual survival of adult females in response to three biologically meaningful environmental variables and their two‐way interactions. Despite the similar ecology of these two species, their survival was associated with different and uncorrelated environmental drivers. The main correlate of Tawny Owl survival was an inverse association with snow depth (winter severity). For Ural Owl, high food (vole) abundance improved survival during years with deep snow, but was less important during years with little snow. In addition, Ural Owl survival was strongly density‐dependent, whereas Tawny Owl survival was not. Our findings advise caution in extrapolating demographic inferences from one species to another, even when they are very closely related and ecologically similar. Analyses including only one or few potential environmental drivers of a species' survival may lead to incomplete conclusions because survival may be affected by several factors and their interactions. 相似文献
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Diego Santiago‐Alarcon Raeann Mettler Gernot Segelbacher H. Martin Schaefer 《Journal of avian biology》2013,44(6):521-530
Parasites can exert strong selection on hosts. Throughout the year migrants are exposed to different sets of parasites, which may affect life history traits such as migratory schedules. Here, we studied the relationship between parasite infection and arrival date of blackcaps Sylvia atricapilla to their breeding grounds in Germany throughout a period of six years (2007–2012). We used two data sets, one that included all blackcaps and one that included only recaptured birds. We assesed whether parasites influence spring arrival to breeding grounds, and for the recaptured data set, we analysed temporal variation in parasitism (i.e. infection status and parasitaemia) throughout the breeding season. We used both microscopy and PCR (a fragment of ? 479 bp of the mtDNA cyt b) to determine haemosporidian infection. Blackcaps were mostly infected with Haemoproteus parabelopolskyi (lineages SYAT01 and SYAT02). Infection status, but not parasitaemia, was constant through time for individual birds; meaning that once a bird is infected, it most likely will retain the infection for life. We found that infection by haemosporidian parasites has no relationship to arrival date in this blackcap population; however, infection by H. parabelopolskyi has a marginally significant effect on arrival date of recaptured blackcaps, somewhat delaying their arrival to breeding grounds. Birds captured later in the season were more likely to be infected than those from early spring, and parasitaemia was frequently lower in birds captured earlier in the season compared to those captured later (summer). 相似文献
98.
Diego Corrêa Alves Carolina Viviana Minte-Vera Angelo Antonio Agostinho Edson Kiyoshi Okada Lilian Paula Vasconcelos 《Reviews in Fish Biology and Fisheries》2013,23(3):375-394
The mathematical and statistical advances in fitting stock assessment models enabled the emergence of the paradigm of “integrated analysis”, which fits all available data to a single model of population dynamics that traditionally has total catch as the only forcing function of the system. This approach, however, allowed us to include, in a flexible way, the effect of hydrological regime as an additional forcing function. We tried to achieve this flexibility by making the annual recruitment rates and spawning biomass adjustable to the attributes of the hydrological cycle data. Our models showed that these attributes are influential in the population dynamics of Brycon hilarii of the Northern Pantanal, and their inclusion in the models allowed best partial fits (which considered fits only to the data components length- and age-compositions, CPUE of juveniles and adults) than the Base-case (without hydrological attributes). The best partial fits where obtained when the attributes “delay of floods” and “intensity of floods” were forcing the spawning biomass and the annual recruitment respectively, indicating that these characteristics of the population may be influenced by specific attributes of the water level. The use of integrated modeling contributed with the advancement of population ecology knowledge of rheophilic fish. It is recommended that freshwater fisheries management be integrated into the hydrology management. 相似文献
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Community structure and species richness of arbuscular mycorrhizal fungi (Phylum Glomeromycota) were studied in sand dune sites at Itapiruba (southern), Joaquina (intermediate) and Praia Grande (northern) beaches along the coast of the state of Santa Catarina, Brazil. In each site, a 20 × 20 m plot was established and 20 soil samples collected in a regular grid pattern. Fungal spores were extracted from each sample, counted and identified to species level. A total of 25 species were recovered belonging to seven genera and five families in the Glomeromycota. Gigaspora albida and Acaulospora scrobiculata occurred in >50 % of samples at all three sites. Other common species whose sample frequency was >50 % in one or two sites were Scutellospora weresubiae, Scutellospora cerradensis and Racocetra gregaria, while the remaining majority of species were detected in <25 % of samples within a given site. Dune sites could be differentiated based on the higher frequency of occurrence of S. cerradensis and Acaulospora morrowiae in Itapiruba, S. weresubiae in Joaquina, and Scutellospora hawaiiensis in Praia Grande. No differences across sites were observed for species richness and total spore numbers, the latter averaging from 28.8 to 31.8 spores per 100 ml soil. Shannon diversity was significantly higher in Praia Grande compared to the other two sites. Differences in the relative spore abundance of genera among dunes were detected only for Scutellospora, which was significantly more abundant in the Joaquina beach. Community structure, as depicted by species rank/log abundance graphs, was not significantly different between areas according to the Kolmogorov–Smirnov two-sample test. Species accumulation curves demonstrated that 13 samples were enough to detect 90 % of all species. Overall, sand dune systems share similar arbuscular mycorrhizal fungal communities despite being geographically distant (150 km) from each other. 相似文献