Pedal surface collecting as an alternative feeding mechanism of the invasive apple snail Pomacea canaliculata (Caenogastropoda: Ampullariidae)

SAVEANU, LUCÍA; MARTÍN, P. R.

JOURNAL OF MOLLUSCAN STUDIES

OXFORD UNIV PRESS

Lugar: Oxford; Año: 2013 vol. 79 p. 11 - 18

0260-1230

Apple snails are freshwater gastropods with highly diverse feeding mechanisms (shredding, scraping and collecting) to exploit diverse food sources. Pomacea canaliculata is listed among the world´s 100 worst invaders, mainly due to its effects on aquatic crops and submersed macrophytes through shredding, its main feeding mechanism. In one of the alternative mechanisms, the snails obtain material from the water surface through a funnel formed by the anterior part of the foot, here termed pedal surface collecting (PSC). Our aims were to study the potential trophic spectrum of PSC and the effects of snail size and sex, density of food particles and particle size on efficiency of this feeding mechanism under laboratory conditions. We also explored occurrence and daily fluctuations in the field. Pomacea canaliculata snails were able to capture different food types irrespective of their physical nature (liquid, organic particles and biofilms) and size, although not all of them could be ingested. PSC was performed only when food was available on the surface by snails from the whole size range tested (3?52.8 mm shell length), although it was less frequent in snails