|
|
||||||||
Biology of Reproduction, Vol 15, 423-428, Copyright © 1976 by Society for the Study of Reproduction
1 Environment Canada,
Fisheries and Marine Service,
Halifax Laboratory,
P. O. Box 429,
Halifax, Nova Scotia B3J 2R3, Canada The effect of 10 ppm of cadmium on eggs of the Pacific herring, Clupea pallasii, incubated in
sea water of 20 percent salinity at 5°C was examined at five stages of development. Eggs exposed
to cadmium hatched approximately 10 days earlier than those of the control; the percentage of
viable hatch was 82.0 in the control and 27.3 for eggs exposed to cadmium; the average size of
viable larvae was 8.46 and 5.49mm respectively. Like the garpike, cadmium uptake by herring eggs
reached its maximum early in the incubation period and was maintained throughout the 5
developmental stages studied; the total uptake was, however, much greater than that reported for
Baltic herring. The relative activity of all four carbon dioxide fixing enzymes studied was depressed by
exposure to cadmium; propionyl CoA carboxylase was depressed before flattening of the blastodisc
stage; PEP carboxykinase depression started prior to closure of the blastopore, whereas NAD- and
NADP-malic enzymes were depressed only prior to the hatching stage. It is postulated that the
relatively small larvae hatching from eggs exposed to cadmium may be the result of: 1) depression
of the relative activity of the carbon dioxide fixing enzymes at different stages of development,
and/or 2) cadmium being bound to the chorion making it vulnerable, thus producing earlier
hatching and premature larvae.
Note:
ACKNOWLEDGMENT
Sincere thanks are due to Dr. V. Dethlefsen,
Cuxhaven, Germany for cadmium determinations. One
of us (H.R.) is supported by the Canadian-German
Scientific and Technical Exchange Programme.
This article has been cited by other articles:
![]() |
D. O. Norris Endocrine Disruptors of the Stress Axis in Natural Populations: How Can We Tell? Integr. Comp. Biol., June 1, 2000; 40(3): 393 - 401. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |