
TY  - JOUR
A1  - Carter, JGT 
A1  - Nicholas, WL 
T1  - Uptake of Zinc by the Aquatic Larvae of <I>Simulium ornatipes</I> (Diptera : Nematocera)
JF  - Marine and Freshwater Research
JO  - Mar. Freshwater Res.
Y1  - 1978
VL  - 29
IS  - 3
SP  - 299
EP  - 309
KW  - 
UR  - https://doi.org/10.1071/MF9780299 
N2  - The uptake and loss of zinc by the aquatic larvae of the blackfly S. ornatipes was investigated using radioactive 65Zn. Larvae may absorb significant quantities of zinc from solution, and a substantial proportion remains in the body when larvae are transferred to zinc-free water. Uptake is assisted by metabolism, but an increase of the calcium ion concentration, although reducing toxicity, has no effect on uptake, exchange or the loss of zinc. Larvae may be fractionated into 'cuticle', 'high-' and 'low-molecular-weight' fractions, based on solubility in water and 80% (v/v) ethanol. In the cuticle and high-molecular-weight fractions two 'pools' may be identified by dialysis against Na3EDTA -a pool in which zinc is weakly held and exchanges rapidly with the zinc in solution, and one where zinc is held and exchanges slowly. Exposure time, temperature, and external concentration influence the quantity of zinc entering these pools. Washing the cuticle and high-molecular-weight fractions with a series of buffers suggests that zinc is bound by phenolic groups in the cuticle fraction, and by phosphonic acids in the high-molecular-weight fraction. Sulfhydryl groups did not bind a major portion of the zinc. 
ER  -

