Dietary cobalt supplements and the growth and reproduction of the earthworm Eisenia foetida |
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| Authors: | Edward F Neuhauser John A Meyer Michael R Malecki John M Thomas |
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| Institution: | Department of Agricultural Engineering, Cornell University, Ithaca, NY 14853-0317, U.S.A. |
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| Abstract: | The effect of adding cobalt, as 60Co, to the food source of the earthworm Eisenia foetida was studied. Cobalt was retained with a half-life of 387 ± 43 (SD) days in the worm. After 172 days more cobalt was concentrated in the gut than the body wall. 60Co was not transmitted from adults to cocoons. Prolonged studies involving the addition of CoCl2 (0, 8.2, 16.5 and 82.5 μg Co g?1) to a food source low in Co indicated that total Co concentrations of 17.6 and 25.9 μg g?1 resulted in significantly increased maximum weights compared to the control worms which were exposed to 9.4 μg Co g?1. The highest Co addition (82.5 μg g?1, total 91.9 μg g?1) caused no increase in maximum weight over controls, but resulted in a statistically significant lag in early growth compared to that of all other groups. Significantly more cocoons were produced by worms fed 17.6 or 25.9 μg Co g?1 compared with those fed 9.4 or 91.9 μg Co?1 Co. |
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