Escape responses to three herbivorous gastropods to the predatory gastropod Conus textile.
ABSTRACT The herbivorous gastropods Strombus canarium, Lambis lambis, and Trochus pyramis evince escape responses, probably mediated by distance chemoreception, in the presence of the predatory gastropod Conus textile.In Strombus and Lambis, the response has two components: increase in the absolute rate of locomotion, and direction of locomotion away from the predator. When placed in the presence of C. textile, T. pyramis began moving, generally in the direction it faced.In control observations, a specimen of S. canarium moved at a mean rate of 2·7 mm/sec, by the leaping mode of locomotion characteristic of this and related genera. In the presence of C. textile, the rate increased to 6·8 mm/sec, due primarily to shortening of the lag or recovery period between leaps. In the presence of C. textile, a specimen of L. lambis moved at a rate of 11·9 mm/sec in the same manner as Strombus. In the presence of C. textile, a specimen of T. pyramis progressed at a rate of 1·9 mm/sec, by pedal locomotory waves.Comparison with absolute rates of locomotion by pedal locomotory waves in other marine gastropod molluscs leads to the conclusion that the leaping of Strombus and Lambis does not enable these gastropods to maintain a more rapid long-term rate of movement, but it confers a striking increase in agility, and a single leap provides an almost instantaneous increase in distance from a potential predator.
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ABSTRACT: Qualitative comparisons of the predator-induced defensive behaviors of four species of trochid gastropod, Margarites pupillus, M. salmoneus, M. rhodia, and Calliostoma ligatum, under controlled laboratory conditions indicate that the degree and strength of the response varies according to the sensory information received from a predator and according to the species of predatory seastar or gastropod inducing the response. Generally, all four species of gastropod demonstrate a weak to moderate avoidance response to the scent of such predatory seastars as Leptasterias hexactis and Pisaster ochraceus; whereas direct contact with their soft parts elicits strong and often violent defensive behaviors characterized by shell twisting, propodial rearing which often leads to a loss of contact with the substrate, and somersaulting by metapodial thrusting. It is hypothesized that the inversion of the shell induced by direct contact with a predator sets up the metapodial thrusting behavior and also part of the righting repertoire, which facilitates more rapid flight from the predator. Margarites spp. respond to the scent and contact with the dire whelk, Searlesia dira; whereas Calliostoma is unresponsive to the snail, but more responsive to the scent and contact of the sunstar Pycnopodia helianthoides than are the other species of gastropods studied.
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ABSTRACT: Differences in behaviour between adult and juvenile Aporrhais occidentalis are related to age-dependent changes in shell morphology and habitat. Juvenile snails right their shells by pulling with the propodium, and do not ‘kick’ at the substratum until the expanded outer lip of the adult shell has formed. Locomotion of juveniles is by arhythmical crawling, with ‘leaping’ taking place only during escape from predators. Adult snails leap during both normal and escape locomotion. Data are presented that demonstrate the importance of the outer lip in stabilizing the shell during leaping locomotion. Escape reactions of A. occidentalis are similar to, but slower than, those reported in the literature for species of strombids. Most of the basic locomotory and shell-righting behaviour patterns seen in the highly specialized Strombidae are observable in the more primitive A. occidentalis. However, the use of the operculum in locomotion and shell righting, although characteristic of the Strombidae, is not found in A. occidentalis. The behaviour of Aporrhais is discussed in relation to evolution within the superfamily Strombacea.Animal Behaviour.
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ABSTRACT: Ocean acidification poses a range of threats to marine invertebrates; however, the potential effects of rising carbon dioxide (CO2) on marine invertebrate behaviour are largely unknown. Marine gastropod conch snails have a modified foot and operculum allowing them to leap backwards rapidly when faced with a predator, such as a venomous cone shell. Here, we show that projected near-future seawater CO2 levels (961 µatm) impair this escape behaviour during a predator-prey interaction. Elevated-CO2 halved the number of snails that jumped from the predator, increased their latency to jump and altered their escape trajectory. Physical ability to jump was not affected by elevated-CO2 indicating instead that decision-making was impaired. Antipredator behaviour was fully restored by treatment with gabazine, a GABA antagonist of some invertebrate nervous systems, indicating potential interference of neurotransmitter receptor function by elevated-CO2, as previously observed in marine fishes. Altered behaviour of marine invertebrates at projected future CO2 levels could have potentially far-reaching implications for marine ecosystems.Proceedings of the Royal Society B: Biological Sciences 01/2014; 281(1774):20132377. · 5.68 Impact Factor