Search results for "species complex"
showing 10 items of 111 documents
Bacteria and free-living amoeba in the Lascaux Cave.
2008
3 pages, 1 table, 18 references. The collaboration of the Lascaux restoration team is highly appreciated. We thank Marisa Chelius for valuable comments on the manuscript.
Resource competition between sympatric sibling rotifer species
2001
Mechanisms underlying competitive interactions are important in understanding the structure of planktonic communities, particularly the coexistence of similar species. Here we present experimental results of exploitative competition among three sympatric sibling species of the Brachionus plicatilis complex for two differently-sized species of food microalgae. These three rotifer species are to be found in seasonal succession in brackish ponds on the Spanish Mediterranean coast; they can, however, co-occur for long periods. The functional and numerical responses of the three Brachionus species to both food microalgae, although similar, differed. Neither rotifer population growth nor grazing …
Dinner with the roommates: trophic niche differentiation and competition in a mutualistic ant‐ant association
2020
1. The potential for competition is highest among species in close association. Despite net benefits for both parties, mutualisms can involve costs, including food competition. This might be true for the two neotropical ants Camponotus femoratus and Crematogaster levior, which share the same nest in a presumably mutualistic association (parabiosis). 2. While each nest involves one Crematogaster and one Camponotus partner, both taxa were recently found to comprise two cryptic species that show no partner preferences and seem ecologically similar. Since these cryptic species often occur in close sympatry, they might need to partition their niches to avoid competitive exclusion. 3. Here, we in…
The origin of two cryptic species of African desert jerboas (Dipodidae: Jaculus)
2011
The desert biota is exposed to extreme and variable conditions that shape its evolution and diversification processes. In this respect, the Jaculus jerboas have gained the attention of researchers as a result of their broad Saharan–Arabian distribution and their high and unexplained, morphological, anatomical, and molecular variation. In the present study, mitochondrial and nuclear genealogies where used to confirm monophyly of two cryptic species: Jaculus jaculus and Jaculus deserti. The reconstructed demography showed that the evolutionary histories of the species are markedly different and that the expansion into North-West Africa by J. deserti was more recent than that of J. jaculus. Th…
Multiple morphological characters needed for field identification of cryptic long‐eared bat species around the Swiss Alps
2010
The identification of cryptic species may significantly change our view about their distribution, abundance, ecology and therefore conservation status. In the European Alps, molecular studies have revealed the existence of three sibling species of plecotine bats Plecotus auritus, Plecotus austriacus and, very recently, Plecotus macrobullaris. Knowledge of the ecological niche partitioning of cryptic species is a requisite to develop sound conservation policies. Yet, this requests the development of unambiguous identification methods easily applicable in the field. This study investigates the reliability of several morphological methods used for species recognition and proposes a new identif…
Lymnaea schirazensis, an Overlooked Snail Distorting Fascioliasis Data: Genotype, Phenotype, Ecology, Worldwide Spread, Susceptibility, Applicability
2011
BackgroundLymnaeid snails transmit medical and veterinary important trematodiases, mainly fascioliasis. Vector specificity of fasciolid parasites defines disease distribution and characteristics. Different lymnaeid species appear linked to different transmission and epidemiological patterns. Pronounced susceptibility differences to absolute resistance have been described among lymnaeid populations. When assessing disease characteristics in different endemic areas, unexpected results were obtained in studies on lymnaeid susceptibility to Fasciola. We undertook studies to understand this disease transmission heterogeneity.Methodology/principal findingsA ten-year study in Iran, Egypt, Spain, t…
Fumonisin production by Gibberella fujikuroi strains fromPinus species
2003
Abstract Fumonisins are important mycotoxins basically produced by strains from the Gibberella fujikuroi species complex (with anamorphs in Fusarium genus) which contaminate food and feed products representing a risk to human and animal health. In this work, we report for the first time the fumonisin production of Fusarium moniliforme Sheldon strains associated to edible pine nuts of Pinus pinea. P. pinea is an important and widely distributed Pinus species in the Mediterranean area where their pine nuts are consumed raw or slightly processed in diverse food products. In this work, characterization and further identification of those strains were performed by polymerase chain reaction-restr…
Phylogenetic analyses of Fusarium graminearum strains from cereals in Italy, and characterisation of their molecular and chemical chemotypes
2014
The Fusarium graminearum species complex (FGSC) is a pathogen of durum wheat and other cereals worldwide. The complex consists of at least 15 species that can produce various mycotoxins, including trichothecenes, associated with human and animals toxicoses. In particular, deoxynivalenol (DON), nivalenol (NIV) and their different acetylated derivatives can be produced by the different chemotypes of the complex. In this study, 90 strains, isolated mainly from wheat in Italy and belonging to the FGSC, were assessed for their phylogeny and their chemotype and trichothecene genotype. Almost all strains of the FGSC belonged to F. graminearum sensu stricto, whereas two strains were F. cortaderiae…
Chromosomal variation and genome size support existence of cryptic species of Triatoma dimidiata with different epidemiological importance as Chagas …
2006
Summary The wide geographical distribution of Triatoma dimidiata, one of the three major vectors of Chagas disease, ranges from Mexico to northern Peru. Since this species occupies a great diversity of artificial and natural ecotopes, its eradication is extremely difficult. In order to assist control efforts, we used chromosome analyses and DNA amount as taxonomic markers to study genetic variability in populations of T. dimidiata from Mexico, Guatemala, El Salvador and Colombia. We differentiated three groups or cytotypes defined by characteristic chromosome C-banding patterns and genome size measured by flow cytometry. The three cytotypes are restricted to different geographic locations. …
DNA barcode reference library for Iberian butterflies enables a continental-scale preview of potential cryptic diversity
2015
How common are cryptic species - those overlooked because of their morphological similarity? Despite its wide-ranging implications for biology and conservation, the answer remains open to debate. Butterflies constitute the best-studied invertebrates, playing a similar role as birds do in providing models for vertebrate biology. An accurate assessment of cryptic diversity in this emblematic group requires meticulous case-by-case assessments, but a preview to highlight cases of particular interest will help to direct future studies. We present a survey of mitochondrial genetic diversity for the butterfly fauna of the Iberian Peninsula with unprecedented resolution (3502 DNA barcodes for all 2…