Early stage with two arms (post-oral).

Stage with three pairs of arms.

Remnants of the larval skeleton in the aboral region of the juvenile.

Non-fenestrated skeleton of antero-lateral arms.

Early with two arms.

Growth of antero-lateral pair of arms (2nd pair).

Arm growing on an unusual site.

View of the macromeres at the vegetal pole.

Stage with four pairs of arms.

Stage with three pairs of arms.

Ring of mesenchyme cells beginning to secrete the calcareous skeleton.

Four-arm stage.

Found during an artificial fertilization experiment. We do not know if it is the result of abnormal development or if the larva was reproducing asexually.

Growth of antero-lateral pair of arms (2nd pair).

Stage with three pairs of arms.

Growth of antero-lateral pair of arms (2nd pair).

Oral region.

Arm growing on an unusual site.

Stage with four pairs of arms.

Stage with three pairs of arms.

Larval epithelium during the growth of the antero-lateral arms (2nd pair).

Stage with four pairs of arms.