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Food limitation. spination, and reproduction in Brachionus calyciflorus
Author(s) -
Stemberger Richard S.
Publication year - 1990
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1990.35.1.0033
Subject(s) - rotifer , brachionus calyciflorus , biology , reproduction , algae , population , hatching , zoology , ecology , demography , sociology
The Brachionus calyciflorus polymorphism involves both a chemical secreted by the predatory rotifer Asplanchna and food concentration. Food concentration accounted for 30–37% of the explained variance in spine length in treatments containing Asplanchna factor. The longest spines developed only in low‐food conditions containing the Asplanchna chemical, indicating that the factors were additive. Newborns exposed only to low concentrations of food during the first 3 d after hatching developed relatively long spines and smaller body sizes than their high‐food‐adapted mothers. The population growth rate of the Asplanchna ‐induced phenotype was significantly higher than that of the short‐spined controls over a wide range of food concentrations (0.4–15.0 µ g ml −1 dry mass of algae). Most importantly, elongated spines were associated with a reduced threshold food concentration for reproduction, suggesting that they return an energetic benefit exceeding their developmental and maintenance costs.