Glutamate, glycine, and especially the secretions of Ruditapes phillipinarum induce efficient foraging by juvenile Rapa whelks

Abstract

Chemical signals are known to influence interactions within and among species of aquatic organisms, including gastropods. However, despite the indispensable roles of chemical signals in species interactions, little is known about their effectiveness, especially in gastropods. The rapa whelk Rapana venosa (Valenciennes, 1846) is an ecologically and economically important gastropod, but it has also become a global invasive species. Currently, bottlenecks exist in the breeding of R. venosa related to foraging behaviour and efficiency in juveniles, while significant problems also exist in controlling invasive populations of the gastropod. Here, we aimed to identify chemical signaling molecules that could effectively improve their foraging behaviour and efficiency and potentially solve the bottlenecks in aquaculture production and control the invasiveness of R. venosa. The foraging behaviour of R. venosa during the search phase was evaluated in response to various signaling molecules as to activity time, motion path, and successful perception rate, and a standard scoring metric was proposed. The results showed that bivalve (Ruditapes philippinarum) secretion and glutamic acid and glycine, could effectively induce foraging behaviour in R. venosa. In contrast, 4-dodecylbenzene sulfonic acid and dodecyl sulfate, did not induce significant foraging behaviour. The induced foraging behaviour by a single amino acid was less effective than that of the entire bivalve secretion. These findings could be helpful in improving breeding efficiency, efficient trapping, and controlling invasive populations of aquatic gastropods.