Morphological effects of different concentrations of commercial disperse red 1 dye in G. tigrina . (a) Individual without full body cicatrization, showing eyespots and no auricles (phase z) - after 120-h exposure at 200 mg/L. (b) Late development of the auricle (phase d) after 120 h at 50 mg/L. (c, d) Individuals with delayed and abnormal cicatrization (phase t) - after 120 h at 200 mg/L. (e) A fully developed planarian with no effect (negative control). Arrows are guides to the eye and the bar on the left of each figure represent 1 mm.