Large variation in toxicity correlates. (a) Progressive increase in muscle dysfunction index (MDI) during adulthood and aging of indicated strains: MDI is 1 when all animals on the plate move spontaneously, and MDI is 3 when all are paralyzed. The curves are a rolling average with a period of 2 days. (b) Internal hatching (bagging) phenotype due to dysfunction in reproductive muscles, scored over the entire egg-laying period. Data are mean ± SD, at least 30 animals per trial, n = 3 trials.