CHD	congenital heart defects/disease
Myo	myocardium
Pc	pericardium
PcB	pericardial body
PcS	pericardial space
L	lumen
TEM	transmission electron microscopy
ATMs	anterior tail muscle precursors
ATM	anterior tail muscles
TVCs	trunk ventral cells
FHPs	first heart precursors
STVCs	second trunk ventral cells
SHPs	second heart precursors
ASMFs	atrial siphon muscle founder cells
ASMPs	atrial siphon muscle precursors
LoM	longitudinal body wall muscles
iASMP	inner atrial siphon muscle precursor
oASMP	outer atrial siphon
OSM	oral siphon muscles
ECM	extracellular matrix