Lakehead University Library Logo
    • Login
    View Item 
    •   Knowledge Commons
    • Research and scholarly works
    • Faculty of Natural Resources Management
    • View Item
    •   Knowledge Commons
    • Research and scholarly works
    • Faculty of Natural Resources Management
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.
    quick search

    Browse

    All of Knowledge CommonsCommunities & CollectionsBy Issue DateAuthorTitleSubjectDisciplineAdvisorCommittee MemberThis CollectionBy Issue DateAuthorTitleSubjectDisciplineAdvisorCommittee Member

    My Account

    Login

    Statistics

    View Usage Statistics

    The enigma of Daphnia death rates

    Thumbnail

    View/Open

    PDF/A (1.895Mb)

    Date

    1978

    Author

    Prepas, Ellie
    Rigler, F.H.

    Subject

    Daphnia pulex
    Daphnia rosea
    Mortality rates
    Population change
    Egg development
    Planktonic crustaceans

    Metadata

    Show full item record

    Abstract

    Birth rates, rates of population change, and mortality rates were computed for Daphnia pulex and Daphnia rosea collected at three separate stations in 2.5-ha meromictic Crawford Lake. Birth and death rates for the same species at the three separate stations, or at the same station but living at slightly different mean depths were substantially different. A correction for tow net efficiency for young and adult animals increased birth rate values by 40%. Mean finite birth rate, B, for Daphnia in a thermally stratified lake is calculated from the relation [see article for formula] where for each stratum, s, E is number of eggs, D is egg development time, N is number of animals, and n is number of strata. An assumption of this formulation is that all individuals in the population behave similarly, but at Crawford Lake D. pulex behaves like two separate populations for at least part of the year. High death rates were calculated for D. rosea in midsummer. A comparison of observed neonates with expected neonates during this period led to the conclusion that most mortality in the population occurs either in late embryos or at hatching.

    URI

    https://www.jstor.org/stable/pdf/2835359.pdf
    http://knowledgecommons.lakeheadu.ca/handle/2453/845

    Collections

    • Faculty of Natural Resources Management

    Citation

    Limnology and Oceanography, 23:5 (1978), pp. 970-988

    Lakehead University Library
    Contact Us | Send Feedback

     


    Lakehead University Library
    Contact Us | Send Feedback