Larva with four pairs of arms and coeloms extended along the gut.

Lateral view.

Early with two arms.

Denominadas pelagosferas, as larvas de muitas espécies de sipuncúlidos são transparentes e nadam livres na água por meses antes de se transformarem no adulto, que tem aspecto vermiforme e vive enterrado na areia ou lodo.

Stage with three pairs of arms.

Epithelial cells with pigmented granules during growth of antero-lateral arms (2nd pair).

Courtship ritual between a male and a female.

Zygote.

Detail of the vestibule near the left coelom and the central gut during early eight-arm stage.

Stage with three pairs of arms.

Early stage with two arms (post-oral).

Anus in the aboral surface of the juvenile (red structure) and fecal pellets being released.