| Fertilized egg | Stage 1 | Stage 1 | Newly laid fertilized egg that did not finish maturation | Segmentation (cleavage) |
| First maturation division | Stage 2 | Stage 1 | First polar body | Segmentation (cleavage) |
| Second maturation division | Stage 3 | Stage 1 | 3 polar bodies | Segmentation (cleavage) |
| 2 cells, first cleavage | Stage 4 | Stage 2 | Two partially separated cells | Segmentation (cleavage) |
| 4 cells, second cleavage | Stage 5 | Stage 3 | Four partially separated cells | Segmentation (cleavage) |
| 8 cells, third cleavage | Stage 6 | Stage 4 | Eight incompletely separated cells | Segmentation (cleavage) |
| 16 cells, fourth cleavage | Stage 7 | Stage 5 | 2 completely closed blastomeres, 14 blastocones | Segmentation (cleavage) |
| 32 cells, fifth cleavage | Stage 8 | Stage 6 | 12 blastomeres, 20 blastocones | Segmentation (cleavage) |
| 64–66 cells, sixth cleavage | Stage 9 | Stage 7 | 36 blastomeres, 28 blastocones | Segmentation (cleavage) |
| Stage I | Stage 10 | Stage 8 | Morula (advanced cleavage) | Segmentation (cleavage) |
| Stage II | Stage 10 | Stage 9 | Blastula | Segmentation (cleavage) |
| Stage III | Stage 11 | Stage 10 | Onset of epiboly | Gastrulation |
| Stage IV | Stage 12 | Stage 11–12 | Formation of the germinal disk (yolk envelope & embryonic proper) | Gastrulation |
| Stage V | Stage 13 | Stage 13 | Epiboly continues | Gastrulation |
| Stage VI | Stage 14–15-16 | Stage 14 | Mesoderm concentrations become more distinct (smooth surface) | Epiboly |
| Stage VII.1 | Stage 17 | Stage 15 | Visible thickening of placodes starts | Epiboly |
| Stage VII.2 | Stage 18 | Stage 15 | Primordia of mantle, eyes, mouth and arms visible | Epiboly/ Organogenesis |
| Stage VIII | Stage 19 | Stage 16 | Mouth and eye invagination, funnel pouches and statocysts visible | Organogenesis |
| Stage IX | Stage 20 | Stage 17 | Primordia more prominent. Funnel tube rudiments are distinct | Organogenesis |
| Stage X | Stage 21 | Stage 18 | Eye vesicles closed and sticking out. Funnel tube rudiments fuse ventrally | Organogenesis |
| Stage XI | Stage 22 | Stage 19 | Mantle starts to grow. Funnel tube rudiments bend towards midline | Organogenesis |
| Stage XII.1 | Stage 23 | Stage 20 | Funnel tube rudiments start to form a tube ventrally. Mantle covers 1/2nd of gills | Organogenesis |
| Stage XII.2 | Stage 23 | Stage 20 | Funnel formed siphon at ventral extremity. Mantle bowl-shaped | Organogenesis |
| Stage XIII | Stage 23 | Stage 21 | Formation of the funnel complete. Iris fold rudiment visible | Organogenesis |
| Stage XIV | Stage 24 | Stage 22 | Mantle as wide as long and covers gills completely | Organogenesis |
| Stage XV.1 | Stage 25 | Stage 23 | Mantle covers ventral margin of funnel. Inner yolk strongly constricted | Organogenesis |
| Stage XV.2 | Stage 26 | Stage 24 | Mouth starts to internalize | Organogenesis |
| Stage XVI | Stage 27 | Stage 25–26 | Few anterior chromatophores evident. Mouth completely covered by arm crown | Organogenesis |
| Stage XVII | Stage 28 | Stage 27 | Mantle enlarged in relation to head. Chromatophores numerous | Organogenesis |
| Stage XVIII.1 | Stage 28 | Stage 27 | Yolk sac same size as head (Octopus & Loligo) | Growth |
| Stage XVIII.2 | Stage 28 | Stage 27 | Chromatophores darker | Growth |
| Stage XIX.1-XIX.2 | Stage 29 | Stage 28 | Pigmentation of ink sac. Eyes covered with iridophores | Growth |
| Stage XX.1 | Stage 29 | Stage 29 | Yolk nearly depleted | Growth |
| Stage XX.2 | Stage 30 | Stage 30 | Loss of outer yolk and hatchling | Growth |
