Smaller
embryos of sea urchins and larger embryos of ascidians (sea squirts)
develop together. Dividing every 45 minutes. At the hollow ball
(blastula) stage smaller sea urchin embryos escape from their
fertilization envelope. The larger ascidian embryos grow a tail
and become tadpoles. Sea Urchin Paracentrotus lividus, Ascidian
Phallusia mamillata, Christian Sardet. link to lab |
