Crowding. Number of offspring from D. pulex grown under moderate crowding conditions with or without melatonin. Delineated is the number of ehippia from the first and second brood (left), and the number of live neonates from the first to the third clutch (right) per individual D. pulex mother. Stars indicate significance (n.s. = not significant) according to GLM (p <0.05, n = 4).