Gastrulation of C. subdepressus.

A Time-series plots with fitted smooth curve of 4 morphometric measurements during gastrulation. The height, width, blastocoel height, and archenteron length were measured every 30 min for 8 h (12–20 hpf, except 12.5 hpf). Height and blastocoel height decreased during the period while the width showed a slight increase; archenteron elongation is continuous. B Relative amount of archenteron elongation during gastrulation calculated by the ratio between archenteron length and blastocoel height. for each timespan.