The penial sheath of Pomacea canaliculata (Ampullariidae). I. The outer gland

GIRAUD-BILLOUD M, GAMARRA-LUQUES C, CASTRO-VAZQUEZ A

Córdoba

Congreso; XXV Reunión Anual de la Sociedad de Biología de Cuyo; 2007

The penial sheath of this snail is a complex structure that includes three glands, with elements probably involved in hormone secretion. We studied here the most conspicuous of them, the so-called “outer gland”. It is orange-yellowish and is located at the sheath’s base. Its thick secretory ducts open in a depression located at the front of the sheath’s insertion on the mantle edge. Abundant mucus is secreted at this point during copulation. The glands’ internal ducts of the gland, and the tubular alveoli in which these end, are lined by a complex cylindrical epithelium, in which goblet cells, ciliated cells and cylindrical secretory cells (loaded with thick granules) are intersped. The basal part of many of the granular cells, as well as some of the goblet cells, protrude towards the submucosa forming a deep stratum which appears sub-epithelial, but whose cells, with their deeply located nuclei, are indeed above the basal membrane and have their apices attaining the lumina of secretory ducts. These granular cells have mitochondria with tubular cristae, and Reinke’s type crystalloids, which are also found in esteroidogenic cells in chordates. The latter crystalloids are embedded in the microgranular matrix of the large granules.