Dinnel et al. (1982) found that EC 50 or LC 50 values for silver and endosulfan tested with 

 sperm or embryos of urchins (Strongylocentrotus droebachiensis) or sand dollars (Dendraster 

 excentricus) were comparable to or slightly higher than those for zooea of crab (Carcinus 

 maenas), Daphnia magna, embryos of oysters (Crassostrea virginica), or rainbow trout (Salmo 



gairdneri). 



D. excentricus sperm were observed to be more sensitive to municipal sewage influents and 

 effluents than C. gigas embryos (Dinnel and Stober, 1987). In most of the tests, they also 

 found that the sensitivity of S. droebachiensis embryo abnormality to sewage exceeded that 

 of fertilization success and mortality of the embryos of the same species and mortality of 

 Cancer magister zooea. In aquatic bioassays of organic compounds and trace metals, Nacci et 

 at. (1986), observed that the sperm cell test was frequently more sensitive than the embryo 

 test with the urchin Arbacia punctulata. Both were generally comparable to the Microtox™ 

 bacterial bioluminescence test in sensitivity; sometimes exceeding it in sensitivity, 

 sometimes not. Both were also generally comparable in sensitivity to bioassays with 

 Pimephales promelas (fathead minnow) and Daphnia magna. 



The utility of cytogenetic/cytologic end-points to augment tests of percent egg 

 fertilization and normal embryo development in S. purpuratus) was suggested by Hose et al. 

 (1983) and Hose (1985). Generally, as the dose of aqueous B(a)p was increased, the number 

 of mitoses per embryo decreased, the percent of mitoses with cytogenetic abnormalities 

 increased, the number of micronuclei per embryo increased, and cytologic abnormalities 

 increased. Also, the fertilization success and normal embryo development decreased. In 

 addition, Bay et al. (1983) proposed use of a test of echinochrome pigment in the urchin 

 bioassay and recorded the sensitivity of this end-point to aqueous copper and lowered 

 salinity. 



In a survey of runoff water and sediments near Newport, California, sediment leachates 

 were generally found to be not toxic to S. purpuratus fertilization success and embryo 

 development (MBC and SCCWRP, 1980). However, as few as 1.1 percent and 1.6 percent of 

 the embryos developed normally in two of the samples. The end-point of normal embryo 

 development appeared to be more sensitive to the same samples than fertilization success. 

 In an evaluation of prospective dredge material from Los Angeles Harbor, MBL (1982) 

 observed significant reductions in either normal development or fertilization success of S. 

 purpuratus or Lytechinus pictus exposed to liquid phase samples. Whereas, fertilization 

 success and normal development exceeded 90 percent in seawater controls, they were less 

 than 33 percent in some samples, and significantly different from controls in samples from 9 

 of 20 stations. In comparison, percent normal development in the present study was below 80 

 percent in only 2 out of 15 samples. However, fertilization success was 70 percent or lower in 

 three out of five samples and in three out of four controls. 



In the present evaluation, the end-points of abnormal development and echinochrome 

 pigment content were not as sensitive as those of abnormal development of M. edulis and of 

 R. abronius. The increased incidences of cytogenetic abnormalities, micronuclei and 

 cytological abnormalities and the decreased number of mitoses per embryo had been 

 demonstrated to be responsive to benzo(a)pyrene (Hose, 1985). In the present evaluation, 

 most of these end-points were sensitive to many of the samples tested and were correlated 

 with increasing concentrations of many contaminants, including hydrocarbons. However, 

 these end-points were evaluated in only five samples and the analytical variability was 

 relatively high. The pattern in response among the samples indicated by the abnormal 

 development end-point contradicted that indicated by many of the other end-points in the 

 same test and in the A. abdita test. This contradiction may be a result of different toxicity 

 mechanisms among these end-points or of unintentional bias in the subjective scoring of 

 embryos as morphologically abnormal versus normal. This contradiction in results has not 

 been observed by the analysts at SCCWRP in previous experience with this test in 

 assessments of complex effluents. In conclusion, it appears that most of the end-points of this 

 test are intermediate in sensitivity, precision, and discriminatory power, but the test should 

 be developed and evaluated further, particularly to refine the mutagenicity and cytological 

 end-points. No test of marine sediment mutagenicity has been widely tested and accepted. 



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