Oxygen Consumption(p2/hr/mg) 
(@) 3 6 12 24 48 
Cadmium Concentration(ppm) 
_ 400 T 
5 dl 
z 
5 375 
= 
2 T 
fo) eos ag Ih 
E 
= 
o 
YO 325 
Figure 1.—Cunner gill tissue oxygen consumption and serum 
osmolality after a 96-hr exposure to cadmium. The upper por- 
tion of the graph represents gill tissue oxygen consumption rate 
(ul/hr/mg) vs. cadmium concentration; the lower portion 
represents serum osmolality (mOsm) vs cadmium. Both curves 
show the mean value and standard error. 
of 3, 6, 12, and 24 ppm cadmium. Oxygen consump- 
tion was slightly higher (0.580 ul/hr/mg) after ex- 
posure to 48 ppm, the same concentration at which os- 
moregulatory stress was observed. These results are 
presented in Figure 1; each point on the curve 
represents the mean value of gill tissue oxygen con- 
sumption of 18 fish. 
DISCUSSION 
Marine teleosts maintain a normal blood serum 
osmolality considerably below that of the surrounding 
medium (Krogh, 1965; Parry, 1966). In the present 
study cunner serum osmolality rose considerably 
above its normal level after a 96-hr exposure to 48 
ppm cadmium. Exposures below this level did not 
alter serum osmolality. Teleost kidneys excrete salts 
and thus maintain a normal osmotic concentration. 
Newman and MacLean (this report, Part VI) detected 
gross pathology in the kidneys of certain cunners used 
in this study. They reported that kidneys of cunners 
exposed to 48 ppm cadmium for 96 hr were nearly 
nonfunctional, while those exposed to cadmium con- 
centrations below 48 ppm appeared normal. Gill and 
gut tissues are also involved in osmoregulatory func- 
tion (Krogh, 1965; Prosser and Brown, 1961). Other 
investigators have reported gill and kidney tissue 
damage in marine teleosts after exposure to cadmium 
(Gardner and Yevich, 1970; Eisler, 1971), and New- 
man and MacLean (this report, Part VI) noted some 
gill and gut damage in cadmium-exposed cunners. 
Osmoregulatory difficulty at 48 ppm is, therefore, ap- 
parently due to kidney failure, although gill and gut 
damage may be contributory. 
Gill tissue oxygen consumption was depressed after 
exposure to 3-48 ppm cadmium. The slight rise 
(although still well below the normal level) in oxygen 
consumption at 48 ppm was attributed to increased 
osmoregulatory stress at that concentration. The 
depression of oxygen consumption may have been due 
to gill damage. Newman and MacLean (this report, 
Part VI) noted gill tissue abnormalities in fish ex- 
posed to cadmium, and Ledgerwood and Brown 
(1973) reported cadmium-induced aneurysms in the 
gill lamellae of threespine sticklebacks, Gasterosteus 
aculeatus. Greig, Adams, and Nelson (this report, 
Part II) found elevated levels of cadmium present in 
gill tissues of all exposed cunners examined. 
In summary, the results of this study demonstrated 
two physiological effects of cadmium on the cunner. 
High levels (48 ppm) of this metal resulted in an ab- 
normally high serum osmolality, and an exposure as 
low as 3 ppm reduced the normal rate of oxygen con- 
sumption. Both of these parameters may be related to 
observed tissue damage. 
LITERATURE CITED 
CALABRESE, A., R. S. COLLIER, and J. E. MILLER. 
1974. Physiological response of the cunner, Tautogolabrus 
adspersus, to cadmium. I. Introduction and experimental 
design. Jn Physiological response of the cunner, Tautogola- 
brus adspersus, to cadmium, p. 1-3. NOAA Tech. Rep. 
NMFS SSRF 681. 
CALABRESE, A., R.S. COLLIER, D. A. NELSON, and J. R 
MacINNES. 
1973. The toxicity of heavy metals to embroys of the 
American oyster Crassostrea virginica. Mar. Biol. (Berl.) 
18:162-166. 
COLLIER, R.S., J. E. MILLER, M.A. DAWSON, and F. P. 
THURBERG. 
In press. Physiological response of the mud crab, Eury- 
Panopeus depressus, to cadmium. Bull. Environ. Contam. 
Toxicol. 
DEAN, J. G., F. L. BOSQUI, and K. H. LANOUETTE. 
1972. Removing heavy metals from waste water. Environ. 
Sci. Technol. 6:518-522. 
EISLER, R. 
1971. Cadmium poisoning in Fundulus heteroclitus (Pisces: 
Cyprinodontidae) and other marine organisms. J. Fish. 
Res. Board Can. 28:1225-1234. 
GARDNER, G.R., and P. P. YEVICH. 
1970. Histological and hematological responses of an estuarine 
teleost tocadmium. J. Fish. Res. Board Can. 27:2185-2196. 
