Figure 8
From: Posterior regeneration in Isodiametra pulchra (Acoela, Acoelomorpha)
Specimens after regenerating for five days. Anterior facing upwards in A and to the left in B-E. White arrowheads point to bursal nozzle. A. Compressed live specimen. B. Sagittal CLSM projection through posterior end. Double arrowheads point to swallow’s nest receptors. C. Ultrathin section through developing vestibulum and bursal wall. D. Histological section through copulatory organs. Note the densely stained stripe in the centre of the penis. E. Ultrathin section through penis epithelium with microvilli on the apical side. Abbreviations: cv, chordoid vacuole; ds, digestive syncytium; fcop, female copulatory organ; m, mouth; mv, microvilli; p, penis; pe, penis epithelium; sbw, seminal bursa wall; sp, sperm; sv, seminal vesicle; ve, vestibulum. Scale bars: A 100 μm; B 25 μm; C 2 μm; D 20 μm; E 5 μm.