Données histologiques sur l'appareil digestif et la digestion des atlantidae (prosobranchia : heteropoda)

The histological structure o f the digestive system and its histophysiological changes during digestion are described in the adults of 6 species of Atlantidae. The results are interpreted functionally and discussed from the point of view of systematics. The digestive tract of the Atlantidae comprises an oesophagus functioning as a crop, a small stomach and a short intestine. A pair of tubular salivary glands and a digestive gland (hepatopancreas) are associated, but oesophageal and rectal glands are lacking. The radular apparatus has the usual prosobranch characters. The digestive tract is totally devoid of mucous cells. Several unicellular glands are in the buccal wall and the anterior part of the oesophagus. There is an apocrine secretion in the crop. Glandular activity is minimal in the stomach and absent in the intestine. [NOT CONTROLLED OCR]