Tornaria

A tornaria is the planktonic larva of some species of Hemichordata such as the acorn worms.^[1][2] It is very similar in appearance to the bipinnaria larvae of starfishes, with convoluted bands of cilia running around the body.^[1] It is an oval shaped, transparent larva. The diameter of the body is about 3 mm. It has an apical plate, which is a thickened region provided by a tuft of cilia and a pair of eye spots. The larva has a complete alimentary canal. The ciliary band stretches throughout the anterior and posterior region, and also the postoral region.

A tornaria larva