and Murchelano 1975), the retardation of growth 

 by heavy metals may be of significance in inhibit- 

 ing regeneration of fins eroded by the benthic 

 substrate. 



Addendum 



It has recently been demonstrated that, in cer- 

 tain poeciliid fishes, some environmental vari- 

 ables which affect general growth rate do not af- 

 fect the rate of fin regeneration. Factors which do 

 cause differences in length of regenerated fin 

 generally affect the time needed for wound heal- 

 ing and blastema formation, rather than rates of 

 regeneration per se (E. Zimmerer, Ph.D. disserta- 

 tion, Rutgers University, 1980). We tested the 

 data represented in Figure 1 for this possibility. 

 In regression analysis, the slope equals regenera- 

 tive rate per se and the elevation (^'-intercept) 

 represents the time needed for wound healing 

 and blastema formation. Analysis of covariance 

 indicates that when Hg treated fish are compared 

 with control fish, both the slopes and j -intercepts 

 are significantly different {F = 10.23 and 80.76, 

 respectively). Similarly, when 10 ppm Zn treated 

 and control fish are compared, the slopes and 

 ^/-intercepts are significantly different {F = 6.83 

 and 41.29, respectively). Therefore, it appears 

 that these heavy metals affect both the initial 

 wound healing and blastema formation and the 

 rate of regeneration per se. 



Acknowledgments 



This work is a result of research sponsored by 

 NOAA Office of Sea Grant, U.S. Department of 

 Commerce, under grant No. 04-7-158-44042. 

 Thanks are extended to J. C. Baiardi of the New 

 York Ocean Science Laboratory for the use of 

 facilities for this study, and to J. Seebode Jr., J. 

 Ricci, and G. Millinger for technical assistance. 

 We thank S. L. Cheng of the New Jersey Institute 

 of Technology for the atomic absorption spec- 

 trophotometry, and J. Chou of the College of 

 Medicine and Dentistry of New Jersey for statis- 

 tical assistance. 



Literature Cited 

 Chang, L. W., l. M. Mak, and a. h. Martin. 



1976. Dose-dependent effects of methylmercury on limb 

 regeneration of newts (Triturus viridescens). Environ. 

 Res. 11:305-309. 



Chang, L. W., K. R. Reuhl, and a. W. Dudley, Jr. 



1974. Effects of methylmercury chloride on Rana pipiens 

 tadpoles. Environ. Res. 8:82-91. 



Crandall, C. a., and C. J. Goodnight. 



1962. Effects of sublethal concentrations of several toxi- 

 cants on growth of the common guppy, Lebistes re- 

 ticulatus. Limnol. Oceanogr. 7:233-239. 

 DIXON, C, AND K. COMPHER. 



1977. The protective action of zinc against the deleterious 

 effects of cadmium in the regenerating forelimb of the 

 adult newt, Notophthalmus viridescens. Growth 

 41:95-103. 



Falchuck, K. H., D. w. Fawcett, and B. L. Vallee. 



1975. Role of zinc in cell division of £ug/en<i graci/is. J. 

 Cell Sci. 17:57-78. 



HiRSCH, K. S., AND L. S. Hurley. 



1978. Relationship of dietary zinc to 6-mercaptopurine 

 teratogenesis and DNA metabolism in the rat. Teratol- 

 ogy 17:303-314. 



RACHLIN, J. W., AND A. PERLMUTTER. 



1969. Response of rainbow trout cells in culture to 

 selected concentrations of zinc sulfate. Prog. Fish-Cult. 

 31:94-98. 

 RAMEL.C. 



1969. Genetic effects of organic mercury compounds. I. 

 Cytological investigations on Allium roots. Hereditas 

 61:208-230. 



Swenerton, H., R. Shrader, and l. S. Hurley. 



1969. Zinc-deficient embryos: reduced thymidine incorpo- 

 ration. Science (Wash., D.C.) 166:1014-1015. 



WEIS, J. S., P. WEIS, AND J. L. RICCI. 



In press. Effects of cadmium, zinc, temperature, and sa- 

 linity on the teratogenicity of methylmercury to the kil- 

 lifish, Fundulus heteroclitus . In Second International 

 Symposium on the Early Life History of Fishes, spon- 

 sored by International Council for the Exploration of the 

 Seas, Woods Hole, Mass., April 2-5, 1979. 



WEIS, P., AND J. S. WEIS. 



1976. Effects of heavy metals on fin regeneration in the 

 killifish, Fundulus heteroclitus. Bull. Environ. Contam. 

 Toxicol. 16:197-202. 



1978. Methylmercury inhibition of fin regeneration in 

 fishes and its interaction with salinity and cad- 

 mium. Estuarine Coastal Mar. Sci. 6:327-334. 

 YAMANE, Y., H. FUKINO, and M. IMAGAWA. 



1977. Suppressive effect of zinc on the toxicity of mer- 

 cury. Chem. Pharm. Bull. (Tokyo) 25:1509-1518. 



ZlSKOWSKI , J. , AND R. MURCHELANO. 



1975. Fin erosion in winter flounder (Pseudopleuronectes 

 americanus) from the New York Bight. Mar. Pollut. 

 Bull. 6:26-28. 



Peddrick Weis 



Department of Anatomy 

 New Jersey Medical School 

 Newark, NJ 07103 



Judith Shulman Weis 



Department of Zoology and Physiology 

 Rutgers, the State University 

 Newark, N J 07102 



166 



