Search results for "freshwater mussel"
showing 5 items of 5 documents
Captive breeding of Margaritifera auricularia (Spengler, 1793) and its conservation importance
2019
Margaritifera auricularia is one of the most endangered freshwater mussels (Bivalvia, Unionida) in the world. Since 2013, the abundance of this species in the Ebro River basin (Spain) has sharply declined, driving the species to the verge of regional extinction. Therefore, any management measures that might facilitate the recovery of this species would be essential for its conservation. During 2014–2016, captive breeding of M. auricularia allowed the production of >106 juveniles, out of which 95% were released into the natural environment, and 5% were grown in the laboratory under controlled conditions. The aim of this experimental work was to establish the best culture conditions for the s…
Parasite transmission in aquatic ecosystems under temperature change: effects of host activity and elimination of parasite larvae by filter‐feeders
2020
A moderate raise in temperature was suggested to enhance the impact of parasites on aquatic ecosystems. Under higher temperatures, poikilothermic animals (e.g. fish) increase their activity, which can result in a more frequent encounter with parasites. However, temperature increase may also trigger processes counteracting an increased risk of parasitic infections. Thus, the removal of free‐living stages of parasites by filter‐feeding organisms can increase with temperature and potentially mitigate disease risk in ecosystems under climate change. We aimed to study whether an increased infection transmission under higher temperatures can be compensated by the increased removal of parasitic la…
Parasites in sympatric populations of native and invasive freshwater bivalves
2021
An increasing threat to local, native freshwater mussels (Unionida)—an ecologically important but globally alarmingly declining group— is the invasion by exotic bivalves. The Enemy Release Hypothesis predicts that introduced species should benefit from enemy-mediated competition because they are less likely to be harmed by natural enemies, such as parasites, than their native competitors. We investigated within-site differences in parasitism between sympatric native (tot. five spp.) and invasive (tot. three spp.) bivalves in eight northern European waterbodies, which harboured totally 15 parasite taxa. In paired comparisons using within-site averages, the mean number of parasite species in …
Conservation of the Giant Freshwater Pearl Mussel (Pseudunio auricularius = Margaritifera auricularia Spengler, 1793) in Spain
2023
Las almejas de agua dulce o náyades son uno de los grupos faunísticos más amenazados del planeta. Entre ellos, la almeja gigante del Ebro o náyade auriculada (Pseudunio auricularius, Spengler 1793) es el bivalvo unionido más amenazado de Europa, y la población de la cuenca del río Ebro en España se encuentra en una situación crítica. El objetivo de esta tesis es aumentar el conocimiento científico del estado de conservación actual de la especie en España con el fin de aplicar acciones de gestión significativas para reducir su riesgo de extinción. El descenso de las poblaciones de náyades (Orden Unionida) en la cuenca del Ebro es generalizado, pero la situación en los canales asociados es cr…
Influence of bed roughness on flow and turbulence structure around a partially-buried, isolated freshwater mussel
2023
The present study uses eddy-resolving numerical simulations to investigate how bed roughness affects flow and turbulence structure around an isolated, partially-buried mussel (Unio elongatulus) aligned with the incoming flow. The rough-bed simulations resolve the flow past the exposed part of a gravel bed, whose surface is obtained from a laboratory experiment that also provides some additional data for validation of the numerical model. Results are also discussed for the limiting case of a horizontal smooth bed. Additionally, the effects of varying the level of burial of the mussel inside the substrate and the discharge through the two mussel siphons are investigated via a set of simulatio…