Nakashima K, Nishino A, Hirose E.

Naturwissenschaften. 2011 Aug;98(8):661-9. doi:10.1007/s00114-011-0815-y

Forming a tough shell via an intracellular matrix and cellular junctions in the tail epidermis of Oikopleura dioica (Chordata: Tunicata: Appendicularia).

In larvae, the tail is enclosed in the larval enveloppe. In adults, the tail fins are made of single triangular epithelial cells attached with tight junctions to the other epitheilal cells covering the tail on the left and right sides. The muscle cells are attached to the epithelial cells via a basal membrane. Up and down the notochord, a sinus separates the muscle cells of each side. In the muscle cells, mitochondria are packed on the exterior side and muscle fibers are on the interior side.