Physiological Response of the Cunner, Tautogolabrus adspersus, 
to Cadmium. 
II. Uptake of Cadmium by Organs and Tissues 
RICHARD A. GREIG, ALBERT E. ADAMS, and BETTY A. NELSON ' 
ABSTRACT 
Cadmium uptake and clearance data were obtained on cunners, Tautogolabrus adspersus, 
exposed to various concentrations of this metal in artificial seawater. 
In the uptake study, cunners were exposed to 0, 3, 6, 12, 24, and 48 ppm cadmium in 
seawater for 4 days. Cadmium residues averaged 8.2 times higher in livers than in gills. At the 
48 ppm cadmium exposure level, the livers averaged 195 ppm, as compared to 33.5 ppm for gills 
(wet weight values). 
In the clearance study, cunners were exposed to 24 ppm cadmium in seawater for 4 days, 
after which time half of the fish were placed in clean flowing seawater for 1 mo and half were 
sacrificed immediately to determine initial cadmium residue concentrations. Gill, liver, blood, 
muscle, and carcass samples were analyzed. Substantial reductions in cadmium residues were 
found in the gills and blood of fish held in clean seawater, as compared to samples from fish 
sacrificed immediately after exposure to cadmium. Liver samples produced variable results: 
livers of fish held in clean seawater for 1 mo contained 62-155 ppm cadmium for four fish and 5- 
11 ppm for three fish, as compared to 30-117 ppm for livers from eight fish sacrificed immediate- 
ly after exposure to cadmium. Muscle and carcass samples from the ‘‘cleared”’ fish showed very 
little reduction in cadmium levels. 
INTRODUCTION 
Freshwater and marine organisms have the ability 
to concentrate metals far in excess of the levels found 
in the waters they inhabit. Mollusks and other 
shellfish, in particular, selectively concentrate 
chemical materials (including metals) up to many 
hundreds of times the levels in their environment 
(Pringle et al., 1968). 
There are three major sources for uptake of metals 
by water-inhabiting organisms: 
1. The water column (the metals are dissolved in 
the water); 
2. Particulate matter (the metals are adsorbed to 
particles suspended in the water column); and 
3. Food (the metals are incorporated in the material 
the organism consumes). 
There are relatively few reports in the literature 
dealing with the uptake of cadmium by marine 
organisms. Of those few marine animals studied for 
cadmium uptake, mollusks have received the most 
attention and finfish the least (Pringle et al., 1968; 
Shuster and Pringle, 1969; Eisler, Zaroogian, and 
Hennekey, 1972). Several investigators have studied 
5 Milford Laboratory, Middle Atlantic Coastal Fisheries Center, 
National Marine Fisheries Service, NOAA, Milford, CT 06460. 
nN 
the toxic effects of cadmium in both freshwater and 
marine finfish, but these workers did not include in- 
formation on the uptake of cadmium (Ball, 1967; 
Gardner and Yevich, 1969, 1970; Roberts, 1963; 
Eisler, 1971). 
Our objective was to obtain data on the uptake of 
cadmium by liver and gill tissues of cunners exposed 
to solutions of CdCl,°2'% H,O in artificial seawater. In 
addition, information was obtained on the extent of 
clearance of cadmium from various tissues and organs 
of cunners that were returned to clean seawater after 
exposure to cadmium. 
METHODS AND MATERIALS 
Fish Holding 
Uptake study.—The methods of exposure of the 
cunner to various concentrations of cadmium chloride 
in artificial seawater for the uptake study are describ- 
ed in Part I of this collaborative report. 
Clearance study.—An independent study was con- 
ducted to determine the extent of clearance of cad- 
mium from various tissues of the cunner, after the ex- 
posed fish were held in clean seawater. Sixteen fish 
were exposed to 24 ppm cadmium (as CdCl.*2'2 H,O) 
in artificial seawater for 96 hr, and eight fish were 
maintained as controls. The fish weighed from 28-89 g 
