Morphology of the digestive gland of the marine panpulmonate limpet Siphonaria lessonii : A cytological, histochemical, and ultrastructural description

LANDRO, SONIA M.; TESO, VALERIA; ARRIGHETTI, FLORENCIA

JOURNAL OF MORPHOLOGY

WILEY-LISS, DIV JOHN WILEY & SONS INC

Año: 2019 vol. 280 p. 1475 - 1484

0362-2525

The molluskan digestive gland has been widely studied and its structural andultrastructural descriptions have allowed the understanding of its several functions.Despite siphonarids are broadly distributed around the world, morphological studies on their digestive system are poorly represented. The panpulmonate limpet Siphonaria lessonii is the most abundant gastropod and the dominant herbivore in the rocky intertidal coast of Buenos Aires. The aim of this study was to describe the morphology, histology, ultrastructure, and histochemistry of the digestive gland of this gastropod as well as the cycle of activity of digestion. For that, different histochemical techniques along with light microscopy, transmission electron microscopy, and scanning electron microscopy were employed. This study revealed a complex epithelium, composed of a simple layer with five cell types. Digestive cells and vacuolatedcells are responsible for intracellular digestion and energy accumulation; basophilic cells, secrete substances that would be involved in extracellular digestion; pigmented cells might have an excretory function and thin cells would correspond to undifferentiated cells. In addition, the tubules present a changing morphology according to the digestive activity that they undergo. As S. lessonii is a grazer that feeds continuously, the cycle of activity of the digestive gland seems to be daily.