Fig. 6

Metamorphosis process and juvenile development in P. mytiligera. a-f Metamorphosis process and early juvenile development, light micrographs of live animals. a-e Body axis rotation stage. a 3 h, b 11 h, c 24 h, d 33 h, and e 45 h post-settlement. f Juvenile stage, 50 h post-settlement. g-o Juvenile development. g-l Light micrographs of live animals. Anterior at top. m-o Histological cross-section, 7 days post-settlement. Scheme of the section level is shown in the lower left corner of each image. Ventral at left. g-h 3 days post-settlement: g 58 h and h 70 h post-settlement. i 5 days post-settlement. j 13 days post-settlement. k-l 58 days post-settlement. Ampulla (A), atrial siphon (AS), anus (AN), tunic blood vessel (BV), body wall (BW), digestive system (DS), endostyle (EN), esophagus (ES), heart (H), neural complex (NC), oral siphon (OS), pigmented sensory organ (SO), protostigmata (PS), stomach (ST), tunic (TU) and tentacles (T1 first order, T2 second order). Scale bar in A-K: 100 μm; in L: 200 μm; in M-O: 50 μm