Illustrated Glossary of Sea Anemone Anatomy - Entire Body Longitudinal Sections

This page features illustrations of sections taken down the long axis of the body of sea anemones. In them it is possible to see structures such as the actinopharynx, mesenteries, and various muscles.

Edwardsia andresi, dissected longitudinally. a. Septa of the posterior portion; b. Septa farther forward, with longitudinal muscles and mesenterial filaments; c. Gullet-tube with septal insertions.
Actinauge rugosa Longitudinal section. cp, infolded capitulum: a, a, tentacles: e, sphincter muscle; d, f, verrucae or tubercles; o, stomodaeum; p, wall of stomodaeum; n, its external layer; m, s, 1-4, perfect mesenteries of 1 to 4 pairs; r, a pair of primary perfect mesenteries; g, ectoderm of body wall; i, endoderm; n, mesogloea; c, circular muscles of body-wall; 1, 1, gonads and mesenterial filaments; b, surface of base; t, section of base.
Actinauge borealis. Longitudinal section of the upper part of the column; e, sphincter muscle; c, retracted capitulum; h, mesogloea; g, ectoderm with remains of dark coating; d, invected disk; t, t', bases of crowded tentacles; v, larger tubercles of the parapet; m, upper ends of the mesenteries, pink in colour; o, oral region of disk.
Entire body longitudinal section of Actinia priapus.
Thelaceros rhizophorae. Inner (endocoelic) face of a mesentery of the first order, with the adjacent exocoelic tentacle. b.w. Body wall, thick in the column and on the base, thin on the disc. l.m. 1, l.m. 3, l.m. 4. Longitudinal muscle. l.m. 2. Parieto-basilar muscle. st. Stomodaeum. g. Genital organ. m.f. Contorted edge of mesentery, with filament.
Octineon lindahli. Much enlarged view of a but little compressed specimen laid open so as to exhibit the essential internal structures (probably a combined, more of less diagrammatic representation). The stomodaeal tube [or rather, the inturned part of the column,] is laid open, and it is seen that the cuticle of the outer surface of the body, with its dense coating of sand and shell particles, is continued to its base. Here it opens into a discoid chamber, which may be called the tentacular chamber [formed by a folding of the oral disc], since [the pouches for] the invaginated tentacles communicate with it all round its periphery by open mouths. [In one of the pouches pointing directly towards the observer, which has been cut across, the tentacle can be seen lying as in a sheath.] In the middle of this chamber below, lies the mouth, leading into the stomach cavity [stomodaeum] below. The latter is surrounded by the radiating retractor muscles, with the ovaries showing beneath them, and by the [sheaths of the] tentacles between the muscles. Six retractor muscles are shown, and eight [sheaths for] tentacles. The directive muscles are apparently the pair on the extreme right and those on the extreme left of the figure [as there is only one entocoelic tentacle sheath between them.

Click below to view relevant images of sea anemone anatomy:


To return to the main page: Illustrated Glossary of Sea Anemone Anatomy

To view our home web site, please follow this link: Division of Invertebrate Zoology

Please send any questions or comments to Bryan McCloskey.