Back to Medium sized version | Without labels
Embryology of sea urchin: 4-cells stage
Legend:
1 fertilization membrane
2 blastomeres (4x)
3 first cleavage plane
4 second cleavage plane
English name: Sea urchin
Scientific name: Psammechinus sp.
Familia: Echinidae
Classis: Echinoidea
Phylum: Echinodermata
Regnum: Animalia
In this isolecithale egg type the cleavage planes are oriented orthogonally (perpendicular) and radially (star-like) relative to each other.
To next stage.
One stage back.
