Alarm response of hatchlings of the apple snail, Pomacea canaliculata (Gastropoda: Ampullariidae), to aqueous extracts of other individuals

Abstract

We examined how hatchlings of the freshwater snail, Pomacea canaliculata, responded to aqueous extracts of conspecific hatchlings. Three, 3‐day‐old hatchlings were macerated in deionized water (1 mg hatchling per 1 ml water). When 0.5 ml of the aqueous extract was added to a test tube containing 10 hatchlings of the same age and 50 ml of water, the hatchlings in the water began to crawl out of the water within 5 min. The proportion of hatchlings that crawled out of the water approached 0.6–0.9 after 1 h, but gradually decreased to 0.4 after 24 h. The relatedness between the live and the macerated hatchlings had no significant influence on the response. Hatchlings of egg masses obtained either in the laboratory or in the wild responded similarly to aqueous extracts of hatchlings from either egg mass. This suggests that the conditions under which the egg masses were incubated or the conditions that their parents had experienced had no effect on the hatchlings’ response. When compared with experiments reported on other aquatic animals, we consider the behavior of the hatchlings to be an alarm response of escaping from predators.

Insights from an Integrated View of the Biology of Apple Snails (Caenogastropoda: Ampullariidae)

“…Ampullariids avoid predators by crawling out of the water, situating themselves near the water surface, burying themselves in the mud, and falling from substrates on which they were crawling (Snyder & Snyder, 1971;Ichinose, 2002;Ichinose et al, 2003;Carlsson et al, 2004b;Aizaki & Yusa, 2009. In P. canaliculata, these behavioral repertoires are size-dependent: hatchlings tend to crawl out of the water; juveniles mainly bury themselves or use near-surface habitats; larger snails are less responsive (Ichinose, 2002).…”

Effects of predation on the exotic freshwater snail Pomacea canaliculata (Caenogastropoda: Ampullariidae) by the indigenous turtle Chinemys reevesii (Testudines: Geoemydidae)

“…P. canaliculata bury themselves in response to the odors of predators or injured conspecifics in the laboratory (Ichinose et al, 2003;Carlsson et al, 2004). Therefore, our experimental results suggest that the snails exhibit self-burial behavior in response to predation, even under semi-natural conditions.…”

Lethal and non‐lethal effects of multiple indigenous predators on the invasive golden apple snail (Pomacea canaliculata)

“…These responses may be initiated by chemical cues released by predators and/or injured conspecifics (Snyder & Snyder, 1971). In addition, P. canaliculata introduced to Japan respond behaviourally to extracts from crushed conspecifics (Ichinose, 2002; Ichinose, Yusa & Yoshida, 2003). In the aquarium trials no size class of snails reacted to chemical cues associated with crabs.…”

“…The same divergent size‐dependent escape response that we found has also been demonstrated for a Japanese population of P. canaliculata exposed to extracts of crushed conspecifics. Smaller snails crawled to the water surface in response to this alarm signal and snails larger than 10 mm buried themselves in the sediment (Ichinose, 2002; Ichinose et al. , 2003).…”