Artificial activation of E. coqui eggs in relation to time after deposition. Unfertilized eggs were treated with calcium ionophore to induce activation at 0 (n = 12), 1 (n = 12), 2 (n = 10), 3 (n = 12), 4 (n = 12), 5 (n = 12), 10 (n = 18), and 24 (n = 18) hours. Eggs were scored for activation by the presence of cleavage furrows at 6 hours post treatment. Note that for the 10 and 24 hour time points, six eggs at each time point had already auto-activated by 6 hours post deposition. At the 10 hour time point, nine additional eggs activated later in response to ionophore treatment, while at 24 hours, no additional eggs were observed to activate after ionophore treatment.