Search for dissertations about: "hatching"

Showing result 1 - 5 of 55 swedish dissertations containing the word hatching.

  2. 1. Effects of abiotic and biotic factors on hatching, emergence and survival in Baltic salmon (Salmo salar L.)

    Author : Eva Brännäs; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Baltic salmon; salmo salar; eggs; egg colour; alevins; fry; photoperiod; temperature; hatching; emergence pattern; synchronization; survival;

    Abstract : This thesis deals with important factors that affect the temporal organization of emergence and early survival of Baltic salmon (Salmo salar L.). The study population was obtained from the Norrfors hatchery (63°50'N,20°05'E), Umeälven (Ume river) in Northern Sweden. READ MORE

  4. 2. Ontogenetic scaling and the development of within-cohort size structure

    Author : Magnus Huss; Lennart Persson; Pär Byström; David Post; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; cannibalism; competition; density-dependence; resource feedbacks; hatching; growth; ontogenetic niche shifts; Perca fluviatilis; size variation; larval fish; Freshwater ecology; Limnisk ekologi; zooekologi; Animal Ecology;

    Abstract : It is increasingly recognized that individuals of the same species differ from each other and influence and respond to their environment in unique ways. This thesis deals with size variation among individuals that not only are of the same species but also of similar age. READ MORE

  5. 3. Embryonic Mortality and Sex Ratios in the Tree Sparrow

    Author : Magnus Svensson; Jan Ekman; Jacob Höglund; Kathryn Arnold; Uppsala universitet; []
    Keywords : Ecology; Hatching success; Embryonic mortality; Sex ratio; Density dependence; Parasites; Ekologi; Passer montanus;

    Abstract : Tree sparrows (Passer montanus) have been studied in two areas in Sweden since 1997. At both sites, tree sparrow eggs had remarkably low hatching success. On average only 60% of the eggs hatched. Analyses have shown that this was caused by embryonic mortality, which was highly sex biased. READ MORE

  6. 4. A flying start : Adapted hatching and post-hatch feeding in broiler chickens

    Author : Malin Boyner; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Keywords : LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Abstract : Conventional hatching practices do not involve provision of feed and water to broiler chickens before placement at the rearing farm. This can pose problems, especially for early hatchlings, which remain feed-restricted for a considerable period due to biological variation in hatch time. READ MORE

  7. 5. Patterns of hatching and adult body mass change in the Pied Flycatcher Ficedula hypoleuca : adaptations and constraints

    Author : Lars Hillström; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP;

    Abstract : .... READ MORE