Die Embryonalentwicklung der Paradiesschnecke ... - TOBIAS-lib

Kapitel 2
gation of internal shells of adult shell-less snails showed that these internal
shells consist of calcium carbonate (unpublished data of R. Osterauer and O.
Eibl, University of Tubingen, Germany). Occasionally, adult individuals display
internal shells bulging out of the snail during further growth (Fig.9C).
As shown in this photograph, also in Pt-exposed snails, all organs and tissues
that develop from the rudimentary shell gland (mantle with mantle edge and
shell gland) become located and, later, remain on the ventral side of the visceral
sac dorsal to the foot throughout the shell-less snail’s life, and usually
are concealed by both the visceral sac and the foot.
Fig. 9: M. cornuarietis, A: histological transverse section of a Pt-exposed embryo, 9-day
old, HE staining; B: Pt-exposed embryo, 9-day old, ventral view; and C: adult shell-less
M. cornuarietis individual (about 4-month old), shell encircled in red, left lateral view.
cn, ctenidium; f, foot; h, head; ls, larval stomach; mt, mantle; mte, mantle edge; op,
operculum; sh, shell; shg, shell gland; tn, tentacle; vs, visceral sac. [Color figure can be
viewed in the online issue, which is available at wileyonlinelibrary.com.]
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