Premium
UPTAKE AND LOSS OF ZINC‐65 IN THE DRAGONFLY PLATHEMIS LYDIA
Author(s) -
Kormondy Edward J.
Publication year - 1965
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.1965.10.3.0427
Subject(s) - zinc , metamorphosis , instar , moulting , larva , zoology , chemistry , isotopes of zinc , dragonfly , biology , ecology , organic chemistry
Study of uptake and loss of zinc‐65 in the dragonfly Plathemis lydia employed concentrations of 0.005 to 0.5 µ c 65 Zn Cl 2 /ml water on 200 early, middle, and late instar larvae. Rate and amount of uptake are independent of temperature (10, 20, and 30C); equilibrium is attained in 24‐48 hr. Loss rate is significantly greater at 10C than at 20 and 30C. Uptake and loss rates are independent of body size (= age), but the amount concentrated is inversely related to body size, the coefficient of accumulation being 68 in small larvae, 28 in larger ones. Total uptake is directly proportional to isotope availability in the medium; owing to experimental error, it could not be determined whether rate of uptake is affected by concentration. Loss rates in the field and the laboratory do not differ. Feeding experiments are inconclusive. Loss rate in dead animals is the same as in live larvae, and 95% of initial activity remains on the cast exuvium at molting and final metamorphosis. Uptake is concluded to be by surface adsorption or cation exchange thereby imposing difficulty in using 65 Zn as an indicator of metabolic activity in energy flow studies. Odonata may function significantly in redistributing zinc, the bulk of which localizes in the upper sediments.