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Community size can affect the signals of ecological drift and niche selection on biodiversity
2020
Made available in DSpace on 2020-12-12T01:24:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-06-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Academy of Finland Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Ecological drift can override the effects of deterministic niche selection on small populations and drive the assembly of some ecological communities. We tested this hypothesis with a unique data set sampled identically in 200 streams in two regions (tropical Brazil and boreal Finland) that differ in macroinvertebrate community size by fivefold. Null models allowed us t…
Semen characteristics and their ability to predict sperm cryopreservation potential of Atlantic cod, Gadus morhua L.
2010
There is a lack of biomarkers or indices that can be used to predict the quality of fish semen samples following the freezing and thawing cycle. In the present study, a series of semen indices were tested to assess if they could accurately forecast the cryopreservation potential of Atlantic cod (Gadus morhua) semen. Fresh and frozen-thawed sperm activity variables were compared, and relationships between frozen-thawed sperm activity and fertilization success were examined. In comparison with fresh sperm, activity variables of frozen-thawed spermatozoa were reduced. Of the 18 males examined, mean (± SEM) spermatocrit of fresh sperm was 40.72 ± 4.23%, osmolality of the seminal plasma 366.32 ±…
Diet Quality Limits Summer Growth of Field Vole Populations
2014
Marked variation occurs in both seasonal and multiannual population density peaks of northern European small mammal species, including voles. The availability of dietary proteins is a key factor limiting the population growth of herbivore species. The objective of this study is to investigate the degree to which protein availability influences the growth of increasing vole populations. We hypothesise that the summer growth of folivorous vole populations is positively associated with dietary protein availability. A field experiment was conducted over a summer reproductive period in 18 vegetated enclosures. Populations of field voles (Microtus agrestis) were randomised amongst three treatment…
Multi-zone marine protected areas: Assessment of ecosystem and fisheries benefits using multiple ecosystem models
2020
12 pages, 8 figures, 3 tables, 1 appendix supplementary data https://doi.org/10.1016/j.ocecoaman.2020.105232
Contribution to the knowledge of Mediterranean wetland vegetation: Lemnetea and Potamogetonetea classes in Western Sicily
2021
The freshwater aquatic vegetation of the Lemnetea and Potamogetonetea classes in Western Sicily was surveyed and analyzed. 85 lakes and small pools were investigated collecting 147 phytosociological unpublished relevés to integrate the very scarce available data (only 3 relevés). By applying statistical analyses on abundances data and on the bases of physiognomy and dominant species, two alliances (Lemnion minoris and Stratiotion) and four different coenoses have been identify for the Lemnetea class; while 11 associations, assigned to two orders (Potamogetonetalia pectinati and Callitricho hamulatae-Ranunculetalia aquatilis) and four alliances (Potamogetonion, Nymphaeion albae, Ranunculion …
Recreational and small-scale fisheries may pose a threat to vulnerable species in coastal and offshore waters of the western Mediterranean
2019
10 pages, 3 figures, supplementary material https://doi.org/10.1093/icesjms/fsz071
Ingestion of microplastics and occurrence of parasite association in Mediterranean anchovy and sardine
2020
10 pages, 6 figures, 1 table, supplementary data https://doi.org/10.1016/j.marpolbul.2020.111399
Community size affects the signals of ecological drift and niche selection on biodiversity
2019
AbstractEcological drift can override the effects of deterministic niche selection on small populations and drive the assembly of small communities. We tested the hypothesis that smaller local communities are more dissimilar among each other because of ecological drift than larger communities, which are mainly structured by niche selection. We used a unique, comprehensive dataset on insect communities sampled identically in a total of 200 streams in climatically different regions (Brazil and Finland) that differ in community size by fivefold. Null models allowed us to estimate the magnitude to which beta diversity deviates from the expectation under a random assembly process while taking di…
Dust and grit matter: abrasives of different size lead to opposing dental microwear textures in experimentally fed sheep (Ovis aries)
2020
ABSTRACT External abrasives ingested along with the herbivore diet are considered main contributors to dental wear, though how the different sizes and concentrations of these abrasives influence wear remains unclear. Dental microwear texture analysis (DMTA) is an established method for dietary reconstruction which describes a tooth9s surface topography on a micrometre scale. The method has yielded conflicting results as to the effect of external abrasives. In the present study, a feeding experiment was performed on sheep (Ovis aries) fed seven diets of different abrasiveness. Our aim was to discern the individual effects of size (4, 50 and 130 µm) and concentration (0%, 4% and 8% of dry mat…
The way wear goes: phytolith-based wear on the dentine–enamel system in guinea pigs (Cavia porcellus)
2019
The effect of phytoliths on tooth wear and function has been contested in studies of animal–plant interactions. For herbivores whose occlusal chewing surface consists of enamel ridges and dentine tissue, the phytoliths might particularly erode the softer dentine, exposing the enamel ridges to different occlusal forces and thus contributing to enamel wear. To test this hypothesis, we fed guinea pigs (Cavia porcellus; n = 36 in six groups) for threeweeks exclusively on dry or fresh forage of low(lucerne), moderate (fresh timothy grass) or very high (bamboo leaves) silica content representing corresponding levels of phytoliths. We quantified the effect of these treatments with measuremen…