Ciona intestinalis early embryonic development ~ from egg to larva ~

 

Image (Description)	Link	Stage	Time after fertilization	Developmental stage	Percentage until hatch	Description	Tail length (µ m)	Ratio tail/head
		1	0.4hr	1cell (fertilized egg )	2%	Zygote, fertilized egg	-	-
			0.8hr		5%		-	-

Image (Description)	Link	Stage	Time after fertilization	Developmental stage	Percentage until hatch	Description	Tail length (µ m)	Ratio tail/head
		2	0.9hr	2cell	6%	Two cell-stage embryo	-	-
		3	1.45hr	4cell	8%	Four cell-stage embryo	-	-
			1.7hr		10%		-	-
		4	1.9hr	8cell	11%	Eight cell-stage embryo	-	-
		5a	2.35hr	early 16cell	13%	Early sixteen-cell stage embryo	-	-
		5b	2.65hr	late 16cell	15%	Late sixteen-cell stage embryo	-	-
		6a	3hr	early 32 cell	17%	Early thirty two-cell stage embryo	-	-
		6b	3.2hr	late 32cell	18%	Late thirty two-cell stage embryo	-	-
		7	3.35hr	44 cell	19%	Fourty four-cell stage embryo. The vegetal side of the embryo is very round.	-	-
		8	4hr	64cell	23%	Sixty four-cell stage embryo. Embryo has a square shape seen form the top, with bulging B7.4 cells.	-	-
		9	4.2hr	76 cell	24%	Seventy six cell stage embryo. The vegetal side of the embryo is very flat	-	-

Image (Description)	Link	Stage	Time after fertilization	Developmental stage	Percentage until hatch	Description	Tail length (µ m)	Ratio tail/head
		10	4.5hr	112cell	26%	Gastrulation starts with the apical constriction of A7.1 blastomeres.	-	-
			4.6hr		27%		-	-
		11	4.9hr	early gastrula	28%	The ntochord has invaginated. The vegetal side of the embryo has a horseshoe shape.	-	-
		12	5.65hr	mid gastrula	32%	Six-row neural plate stage. The blastopore is still central and open.	-	-
		13	5.9hr	late gastrula	34%	The blastopore is in posterior position and nearly closed. The embryo elongates anteriorly. The neural plate has more than 6 rows and the A-line neural rows (I and II) start to curve (neurulation begin). The large b6.5 progeny are coming together at the midline.	-	-

Image (Description)	Link	Stage	Time after fertilization	Developmental stage	Percentage until hatch	Description	Tail length (µ m)	Ratio tail/head
		14	6.35hr	early neurula	36%	A-line neural plate forms a gutter lined by b6.5 descendants. The embryo has a diamond shape. The gutter is not closed.	-	-
		15	6.8hr	mid neurula	39%	The neural tube has formed on most of its length. The embryo has an oval shape. The a-line neural plate also forms a gutter.	83.0	1.0
		16	7.4hr	late neurula	42%	The neural tube starts to form in the posterior territories. The embryo elongates.	84.2	1.0

Image (Description)	Link	Stage	Time after fertilization	Developmental stage	Percentage until hatch	Description	Tail length (µ m)	Ratio tail/head
		17	8.45hr	initial tailbud I	48%	First indication of a separation between tail and trunk territories. The tail is not bent and has the same length as the trunk. Any notochord cells not finished intercalation.	87.8	1.0
		18	8.8hr	initial tailbud II	50%	The tail is clearly separated from the trunk. Tail and trunk have same length. Neuropore still open, a-line neurulation.	111.9	1.1
		19	9.3hr	early tailbud I	53%	The tail bends about 40°and is slightly longer than the trunk. A few anterior most notochord cells begin to intercalate and linear.	120.3	1.2
		20	9.5hr	early tailbud II	54%	Neuropore closed, tail bent by 60°, neurulation complete.	146.7	1.3
		21	10.0hr	mid tailbud I	57%	Tail 1 1/2 times longer than trunk and curve ventrally (90°). Intercalation of notochord cells just finished.	180.7	1.6
		22	10.9hr	mid tailbud II	62%	The body adopts a half circle shape. Tail twice as long as trunk.	221.2	1.9
		23	11.9hr	late tailbud I	68%	Initiation of the pigmentation of the otolith. Tail strongly curved with tip close to the anterior end of the trunk.	255.1	2.1
			12hr		69%		-	-
		24	13.5hr	late tailbud II	77%	Notochord vacuolation begins, palps start to be visible at the front end of the embryo. Tail straightens.	442.6	3.4
		25	15.9hr	late tailbud III	91%	Ocellus melanization. All notochord cells have vacuoles. Tail bent dorsally.	558.6	3.9
			16.5hr		94%		-	-
			17.0hr		97%		-	-

Image (Description)	Link	Stage	Time after fertilization	Developmental stage	Percentage until hatch	Description	Tail length (µ m)	Ratio tail/head
		26	17.5hr	hatching larva	100%	Hatching. head adopts an elongated rectangular shape.	661.6	4.2