Table 1.

Developmental age of early cardiac morphological events in different species. Adapted from Fishman and Chien (1997).

	Human	Mouse	Chick	Frog	Zebrafish
Migration of precardiac cells from epiblast	15-16 days	E7	HH4	Stage 10	5.5 hpf
First evident assembly of myocardial plate	18 days	E7	HH5	∼Stage 13	∼13 hpf
Generation of single heart tube initiated	22 days	E8	HH9	Stage 28	∼19 hpf
Tubular heart starts contraction	23 days	E8.5	HH10	∼Stage 33	22 hpf
Looping	23 days	E8.5	HH11	Stage 33-36	33 hpf
Cushions form	28 days	E9.5	HH17	∼Stage 41	48 hpf

Fishman MC, Chien KR. 1997. Fashioning the vertebrate heart: earliest embryonic decisions. Development 124(11):2099-2117.