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Visar resultat 6 - 10 av 10 avhandlingar som matchar ovanstående sökkriterier.

  1. 6. Sex-role reversal in two pipefish (Syngnathidae) species : paternal care and male limitation of female reproductive success

    Författare :Ingrid Ahnesjö; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : .... LÄS MER

  3. 7. Mutual Mate Choice in the Deep Snouted Pipefish Syngnathus typhle

    Författare :Maria Widemo; John D. Reynolds; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; Sexual selection; mutual mate choice; mate competition; sex role reversal; parental investment; Biologi; Biology; Biologi; Animal Ecology; zooekologi;

    Sammanfattning : This thesis integrates the fields of sexual selection, parental investment and sex role theory by investigating mutual mate choice and mate competition in the sex role reversed deep snouted pipefish Syngnathus typhle (Pisces: Syngnathidae) through a series of laboratory experiments. In S. LÄS MER

  4. 8. Mate choice and sexual selection in two species of sex-role reversed pipefish (Syngnathidae)

    Författare :Gunilla Rosenqvist; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : .... LÄS MER

  5. 9. Sperm motility in Gasterosteiform fishes : The role of salinity and ovarian fluid

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

    Sammanfattning : 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. LÄS MER

  7. 10. Egg size evolution and paternal care in pipefishes

    Författare :Inês Braga Gonçalves; Göteborgs universitet; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER