Search results for "specialist species"
showing 10 items of 80 documents
Drivers of parasite community structure in fishes of the continental shelf of the Western Mediterranean: the importance of host phylogeny and autecol…
2019
15 pages, 5 figures, 6 tables, supplementary data https://doi.org/10.1016/j.ijpara.2019.04.004
Review paper: Seasonal variation as a determinant of population structure in rotifers reproducing by cyclical parthenogenesis
1998
Monogonont rotifers live in habitats that display extensively variation in both biotic and abiotic components. Much of this variation is seasonal and therefore predictable for a given pond or lake. In 1972, King proposed one physiological and two genetic models presenting alternative modes of adaptation to this temporal variation. Our purpose in the present paper is to review and evaluate how our knowledge of the seasonal structure of rotifer populations has changed in the past 25 years. Seasonal changes in clone frequencies have been reported from three studies of natural populations using electrophoretic analysis of isozymes. In one of these studies there was evidence for substantial temp…
Environmental drivers of breeding sites in blackfly species of medical and veterinary importance in eastern Spain
2021
Geographical distribution and abundance of the pupae of six blackfly species of medical and veterinary concern were studied in eastern Spain according to three different sets of explanatory variables including in-stream variables, both (i) abiotic (i.e., physicochemical) and (ii) biotic (i.e., richness and abundance of either taxonomically or ecologically close related taxa), as well as (iii) meteorological and landscape variables. The results showed specific habitat requirements for pupation in Simulium (Boophthora) erythrocephalum (De Geer, 1776) and Simulium (Wilhelmia) equinum (Linnaeus, 1758), two of the six species studied regarding elevation and temperature. While the rest of the spe…
Corrigendum to “Conservation value of forest plantations for bird communities in western Kenya” [Forest Ecol. Manag. 255 (2008) 3885–3892]
2009
A re-analysis of the bird data revealed a mistake within the database query. Only bird individuals that were heard were integrated in the results leading to lower total richness and number of individuals. In total 115 species and 13,331 individuals were detected of which 41 were forest specialists (43% of all individuals), 40 forest generalists (41%) and 34 forest visitors (16%). The statistical analyses remain very similar. We recorded significant differences in mean bird species richness, number of individuals and relative species richness among the five forest types (Table 1). Multiple pairwise comparisons showed significantly higher numbers of species in natural forest, mixed indigenous…
Solapamiento del nicho trófico en un área de cría en la costa portuguesa
2002
The diets and the trophic niche overlap between seven flatfish species were studied in a coastal nursery adjoining to the Tagus estuary (Portugal). Fish were sampled monthly, from March to November 1999, using a beach seine. Arnoglossus imperialis (Rafinesque, 1810), Arnoglossus laterna (Walbaum, 1792) and Arnoglossus thori Kyle, 1913, fed mainly on crustaceans. The diets of Buglossidium luteum (Risso, 1810) and Dicologoglossa cuneata (Moreau, 1881) were mainly composed of Bivalvia and Polychaeta, while for Scophthalmus rhombus (Linnaeus, 1758) the main food items were Mysidacea and Teleostei. The diet of Pegusa lascaris (Risso, 1810) was mainly composed by Cumacea, Bivalvia, Decapoda and A…
HELMINTH ASSEMBLAGES OF WHITEFISH (COREGONUS LAVARETUS) IN INTERCONNECTED LAKES: SIMILARITY AS A FUNCTION OF SPECIES SPECIFIC PARASITES AND GEOGRAPHI…
2004
This article examined the composition of parasite assemblages of whitefish (Coregonus lavaretus) in 8 interconnected lakes in northeastern Finland and evaluated the role of coregonid specific parasites and the geographical distance between populations in determining the similarity of the assemblages. Parasite assemblages were compared using the Jaccard qualitative similarity index and a quantitative similarity index and by incorporating the allogenic-autogenic species concept and the effects of 2 corresponding measures of geographical distance between the lakes. The majority of the parasite species found (10 of 14) were specific to salmonids. Similarity of assemblages of autogenic parasites…
Host–virus evolutionary dynamics with specialist and generalist infection strategies: Bifurcations, bistability, and chaos
2019
In this work, we have investigated the evolutionary dynamics of a generalist pathogen, e.g., a virus population, that evolves toward specialization in an environment with multiple host types. We have particularly explored under which conditions generalist viral strains may rise in frequency and coexist with specialist strains or even dominate the population. By means of a nonlinear mathematical model and bifurcation analysis, we have determined the theoretical conditions for stability of nine identified equilibria and provided biological interpretation in terms of the infection rates for the viral specialist and generalist strains. By means of a stability diagram, we identified stable fixed…
Environmental distribution of prokaryotic taxa
2010
14 pages, 5 figures, 1 table, 10 additional files avalaible [http://www.biomedcentral.com/content/supplementary/1471-2180-10- 85-S10.PDF ]
Niche segregation of coexisting Arctic charr (Salvelinus alpinus) and brown trout (Salmo trutta) constrains food web coupling in subarctic lakes
2012
SUMMARY 1. Generalist fish species are recognised as important couplers of benthic and pelagic food-web compartments in lakes. However, interspecific niche segregation and individual specialisation may limit the potential for generalistic feeding behaviour. 2. We studied summer habitat use, stomach contents and stable isotopic compositions of the generalist feeder Arctic charr coexisting with its common resource competitor brown trout in five subarctic lakes in northern Norway to reveal population-level and individual-level niche plasticity. 3. Charr and trout showed partial niche segregation in all five lakes. Charr used all habitat types and a wide variety of invertebrate prey including z…
Factors affecting the distribution of recent lacustrine ostracoda from the Caicedo de Yuso-Arreo Lake (Western Ebro Basin, Spain)
2005
Recent Ostracoda assemblages of the Caicedo de Yuso Lake have been described as representative of palustrine/lacustrine environments in Iberian temperate lakes. This study considers the changes in assemblages at a fixed station during two consecutive annual cycles, as well as their distribution in summer and winter profiles of the lake. Total sample-assemblages have been quantified as species diversities, measured by the Shannon-Wiener index H (S). The trends of this index are compared to physical parameters (temperature, conductivity, dissolved oxygen, CO2) of the bottom waters of this lake. The Ostracoda assemblages (8100 adults and juvenile living specimens, belonging to 20 species) are …