Evidence for maternal transmission of a putative endosymbiont in the digestive gland of Pomacea canaliculata (Architaenioglossa, Ampullariidae)

KOCH, E.; VEGA, I.A.; CASTRO-VAZQUEZ, A.

BIOCELL

IHEM-CONICET

Lugar: Mendoza; Año: 2017 vol. 41 p. 59 - 61

The digestive gland of the apple snail Pomacea canaliculata lodges two types of pigmentedcorpuscles (identified as C and K corpuscles) which has been proposed as endosymbiont/s. Bothcorpuscular types are always present in the digestive gland of adult snails, they are released into thetubuloacinar lumen and are later expelled in the feces. On their part, hatchlings lack any C or K corpusclesin the digestive gland as well as in their feces, whereas C corpuscles appear in both the gland andfeces within one week after hatching. Hence, it is possible that the detritivorous hatchlings acquire theputative C-endosymbiont from feces in the sediments where they live, i.e. through ?lateral? or ?horizontal?transmission. This possibility was put to test in an experiment in which we prevented any lateraltransmission, by a 7-days aseptic culture, with no food, of aseptically obtained hatchlings. At the end ofthe experiment, we observed that most juveniles had survived the culture period, and hence the digestiveglands and feces of survivors were studied by light microscopy of resin embedded, toluidine blue-stainedsections. All studied glands and fecal samples showed C corpuscles. It is concluded that lateral transmissionof the endosymbiont, if any, is not indispensable for the acquisition of the endosymbiont by hatchlings.