UBC Theses and Dissertations
Magnesium regulation in Aedes campestris larvae Kiceniuk, Joe Willie
Regulation of hemolymph and whole-body Mg ++ concentration was studied in the larvae of Aedes campestris Dyar and Knab from a salt-lake containing 190 m Eq Mg++/litre. Hemolymph Mg++ concentration of the larvae responded quickly to a change in external Mg++ concentration and reached a new level after one day. Over a wide range (0.02 to 200 m Eq/litre) of external Mg++ concentrations the blood Mg++ concentration changed only from 4 to 8 m Eq/litre. The rate of entry of Mg++ into the larvae by drinking was 19 to 57 n Eq/mg x hr. Drinking rate was found to be independent of temperature (10C- 22C), Mg++ concentration (100- 300 m Eq/litre), and presence of particles in the medium. More than 95% of the ingested Mg++ was absorbed from the midgut. Whole-body Mg++ content of larvae remained low, indicating that excess Mg++ was not stored in tissue. Measurement of urine Mg++ concentrations of animals in different media showed that excretion via urine could account for all of the ingested Mg++. Anal papillae need not therefore be implicated in Mg++ excretion in Aedes campestris larvae.
Item Citations and Data