Search for dissertations about: "Eggs"

Showing result 11 - 15 of 142 swedish dissertations containing the word Eggs.

  2. 11. Comparative avian developmental toxicity of PFAAs

    Author : Marcus Nordén; Magnus Engwall; Krister Halldin; Anders Bignert; Örebro universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; chicken; herring gull; cormorant; PFAA; PFOS; PFOA; toxicity; levels; Biology; Biologi;

    Abstract : Perfluoroalkyl acids (PFAAs) are persistent organic pollutants that can commonly be found in environmental matrixes and wildlife from all over the globe. The PFAAs have been used in applications such as water and dirt repelling treatments for textiles, oil-resistant paper coatings and fire-fighting foams. READ MORE

  4. 12. Mapping of an extracellular pacemaker in avian egg integuments and its non-invasive monitoring

    Author : Stig G. Ollmar; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : Several local bio-electrical rhythms occur in the integuments, i.e. the shell and shell membranes, of both fertilized and unfertilized eggs. The phenomenon has been found in more than 20 different species and is likely to be ubiquitous mithin eggs from all avian species. READ MORE

  5. 13. MODEL STUDIES OF FISH EGG AND LARVAL TRANSPORT IN THE KATTEGAT AND THE NORTH ATLANTIC

    Author : Selma Pacariz; Göteborgs universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Oceanography; Fisheries;

    Abstract : For the early life stages of fish, the dispersal and retention are important factors regarding present and future survivorship, growth and reproduction. The main objective of this thesis is to analyse fish egg and larval transport in two different marine systems, the Kattegat and the North Atlantic. READ MORE

  6. 14. Egg size evolution and paternal care in pipefishes

    Author : Inês Braga Gonçalves; Göteborgs universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Egg size; embryo development; embryo survival; hypoxia; male quality; mate choice; mating constraints; oxygen; parental care; parental effects; paternal care; reproductive compensation; sex-role reversal; sexual conflict; Syngnathidae; Syngnathus typhle;

    Abstract : In this thesis I explore how sexual selection, sexual conflicts, coevolution with parental care and an environmental selective agent (hypoxia) affect the evolution of different egg characteristics and embryo survival and size in pipefishes (Syngnathidae). In the broad-nosed pipefish, Syngnathus typhle Linnaeus, both sexes prefer to mate with large partners; large females produce more and larger eggs and large males can care for more young, and, as shown in this thesis, invest more per embryo and provide better oxygenation during brooding. READ MORE

  7. 15. Sperm motility in Gasterosteiform fishes : The role of salinity and ovarian fluid

    Author : Helena Elofsson; Bertil Borg; Matthew Gage; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Biology; Biologi;

    Abstract : In externally fertilising fishes, various factors in the surrounding environment may influence the viability of the sperm and eggs, thus determining the success of reproduction. In this thesis, the influence of salinity and ovarian fluid on sperm motility has been investigated in three Gasterosteiform fishes. READ MORE