Internal anatomy and histology of Edwardsiella andrillae n. sp.

All scale bars =100µm unless otherwise noted. A. Cross section through actinopharynx showing mesenteries and siphonoglyph. Scale = 500µm. B. Cross section through tentacle showing relatively strong ectodermal musculature and abundant spirocysts. C. Longitudinal section through oral disc showing relatively weak ectodermal musculature. Scale bar =20 µm. D. Gametogenic region of mesentery of female specimen. E. Cross section through distal column showing microcnemes. F. Close-up view of actinopharynx, showing histological differentiation of siphonoglyph. G. Trophonema of mature oocyte. Scale bar =30 µm. H. Retractor and parietal muscle of macrocnemic mesentery. I. Retractor muscle of Macrocneme. J. Musculature of base of tentacle. K. Junction between aboral end and mesentery. Note absence of basilar muscles. Scale bar =25 µm. L. Longitudinal section through distal column showing transition between tentacle and capitulum. M. Longitudinal section through scapus. Scale bar =30 µm. N. Longitudinal section through aboral end.

Abbreviations: Apx, actinopharynx; Cap; capituluar ectoderm; DD, dorsal directive mesentery; DL, dorsolateral mesentery; G, gastrodermal side of body wall; P; junction of mesentery and retractor muscle; S, siphonoglyph; T, tentacle; VD, ventrolateral directive mesentery; VL, ventrolateral mesentery.