After the second check details paired feeding, more than 50% of the Cantareus snails turned around and moved toward the odorant, and after eight paired feedings, 100% of the Cantareus test snails turned around to approach the odorant. In contrast, the Euglandina’s performance never got above chance. At best, only 50% of the Euglandina snails turned toward the odor (after nine paired feedings), and there was no trend with increasing numbers of paired feedings (Fig. 8B). The apparent inability of Euglandina to learn to travel toward novel odors associated with food is in marked contrast to their ability to learn Inhibitors,research,lifescience,medical to follow artificial trails of

novel chemicals. Previous experiments with nonvolatile compounds showed that Euglandina learn to follow novel trails after one to three paired feedings (Clifford et al. 2003), and can learn to follow artificial trails paired with exposure to a potential mate as well as exposure to food (Shaheen et al. 2005). To rule out the possibility that the Euglandina’s poor learning Inhibitors,research,lifescience,medical performance might be due to an inability to detect the volatile compounds Inhibitors,research,lifescience,medical that were used, we tested their ability to learn to follow an artificial trail of a new odorant molecule. After a baseline trial with an artificial trail of 10% anise oil, we fed test Euglandina prey snails paired with

Inhibitors,research,lifescience,medical a solution of 10% anise oil. Twenty-four hours later, the snails were placed near an artificial trail of dilute anise oil and observed for trail following. Similar to what we have previously observed with nonvolatile artificial trails (Clifford et al. 2003), after a single paired feeding 50% of the test snails followed the artificial trail, with 80% of them following after two paired feedings. Discussion Laboratory experiments with the predatory snail Euglandina have shown that Inhibitors,research,lifescience,medical these snails have a highly developed ability to detect mucus from other snails and slugs and to select a response to mucus cues from a repertoire of several behaviors. Previous work has shown that based

on cues in mucus, Euglandina can distinguish between prey snails and conspecifics as well as favored and enough unfavored prey species (Cook 1989; Clifford et al. 2003; Meyer and Cowie 2010) reacting differently to mucus trails depending on the identity of the trail layer. In the laboratory, the snails can tell the directionality only of conspecific trials, apparently by distinguishing the right side of the trail from the left (Shaheen et al. 2005), while in the wild, the snails appear to be able to determine trail directionality from prey trails as well (Davis-Berg 2011). Euglandina also rapidly learn to follow trails of novel chemicals associated with either prey snails or potential mates (Shaheen et al. 2005).