Sökning: "Asellus aquaticus"

Visar resultat 1 - 5 av 8 avhandlingar innehållade orden Asellus aquaticus.

1. 1. Behaviour under predation risk - antipredator strategies, behavioural syndromes and sex-specific responses in aquatic prey

   Författare :Sanna Harris; Biodiversitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; phenotypic integration; Poecilia reticulata; Asellus aquaticus; behavioural syndromes; chemical cues; predation; antipredator behaviour;

   Sammanfattning : In many natural ecosystems, predation is well recognized as a strong evolutionary force, and predator-mediated selection has been demonstrated to induce changes in prey morphology, life history and behaviour. In my thesis, I have focused on behavioural responses in aquatic prey under the risk of predation. LÄS MER

3. 2. Mating strategies and sexual conflicts in aquatic invertebrates: consequences for evolutionary differentiation

   Författare :Kristina Karlsson; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Asellus aquaticus; Dytiscidae; gender bias; genetic polymorphism; mate guarding; parallel evolution; plasticity; population divergence; sexual conflict; sexually antagonistic selection; sexual selection;

   Sammanfattning : In this thesis I investigated how mating related strategies may differ among populations and how these strategies evolve in response to their local ecological environments. I have used two different study systems of aquatic invertebrates: diving beetles (Dytiscidae) and the fresh water isopod Asellus aquaticus. LÄS MER

4. 3. Local adaptive pigmentation in Asellus aquaticus -effects of UV-radiation and predation regime

   Författare :Jonas Johansson; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Marinbiologi; limnology; aquatic ecology; marine biology; Hydrobiology; Ekologi; Ecology; damselfly; perch; UV-avoidance; isopod; anti-predator traits; evolution; selective predation; limnologi; akvatisk ekologi; Animal ecology; Djurekologi;

   Sammanfattning : Pigmentation in the freshwater isopod Asellus aquaticus differed between two habitats. Asellus were lighter pigmented in stands of submerged stonewort vegetation, than in nearby reed stands. Moreover, Asellus pigmentation became lighter with time in recently established stonewort stands. LÄS MER

5. 4. On the Environmental Relevance of Platinum Group Elements

   Författare :Sebastien Rauch; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; platinum; ICP-MS; automobile emission; catalyst ageing; palladium; laser ablation; urban particles; bioaccumulation; rhodium;

   Sammanfattning : It has recently been demonstrated that platinum group elements (PGE) are released from automobile catalysts into the environment, raising concern over ecological and human health risks. However, there is still a lack of knowledge regarding the dispersion and transformation of PGE in the environment and it is therefore difficult to assess potential risks. LÄS MER

7. 5. Mixture toxicity of pesticides and biological effects in agricultural streams : field and laboratory studies

   Författare :Jenny Rydh Stenström; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : The main objective of this thesis was to examine pesticide mixture toxicity and its effects on aquatic biota in agricultural streams. This was accomplished by (1) calculating the ΣTUs for algae and Daphnia magna and a pesticide toxicity index (PTI) based on water quality standards (WQS) for long-term monitoring data (2002-2010), (2) by performing algal inhibition tests with Pseudokirchneriella subcapitata, using both collected in situ water samples and reconstituted water spiked with field-observed pesticide mixtures, and (3) by studying seasonal changes in macroinvertebrate and diatom communities during 2008 in four agricultural streams and determine a set of community-based metrics such as species richness, diversity, ASPT, SPEAR and IPS. LÄS MER