Non lumenized caudal fin sprout at 2.5 dpf. Time-lapse confocal imaging of Tg(kdrl:EGFP)s843; Tg(gata:dsRED)sd2 double transgenic embryos, where all ECs are labelled in green, and all erythrocytes are labelled in. Note the non lumenized sprout at 2.5 dpf. Scale Bar: 20 μm.