Growth, Mortality, and Feeding Rates of the Snail Helix Aspersa at Different Population Densities in the Laboratory, and the Depression of Activity of Helicid Snails by Other Individuals, or Their Mucus

Abstract

When reared at high densities, young Helix aspersa show less shell growth, even if waste products are removed. They also feed less, and show increased mortality. It is suggested that these effects are linked to reduced activity. Juveniles show reduced activity in the presence of adults or their mucus. Mucus of adult Cepaea nemoralis also depresses the activity of both adult and young Helix and Cepaea.

Influence of egg cannibalism on growth, survival and feeding in hatchlings of the land snail Helix aspersa Müller (gastropoda, pulmonata, stylommatophora)

“…In this experiment, assimilation efficiency was similar to those recorded by Charrier and Daguzan (1980) and Lamotte and Stem (1987 (Pallant, 1974 (Desbuquois, 1991) and snails' density (Dan and Bailey, 1982;Gomot et al, 1989;Lucarz and Gomot, 1985) are known to influence the growth of H aspersa. In contrast to this experiment, farm snails are fed with a compound food and maintained in group at an optimum density.…”

Spatial Distribution of a Population of SnailsHelix aspersa maxima(Mollusc, Gastropoda) in Outdoor Rearing Parks

“…However, experiments conducted in laboratory, where food was given ad libitum, also exhibit the negative influence of high densities, especially in Cepaeu (Tilling, 1985) and Helix (Daguzan, 1985;Lucarz and Gomot, 1985;Blanc and Attia, 1992). Moreover, Dan and Bailey (1982) have shown, for the same species and in closed rearing, the negative effect of the accumulation of the mucus which leads to a reduction of behavioural activities and therefore, to a reduction of growth.…”

Reproduction of <i>Omalonyx matheroni</i> (Gastropoda: Succineidae) under laboratory conditions

“…Several studies demonstrated that crowding increases mortality and decreases the growth rate of snails (Charrier 1981, Lazaridou-Dimitriadou & Daguzan 1981, Dan & Bailey 1982, Lucarz & Gomot 1985, Jess & Marks 1995 and that snails reared in isolated conditions presented less variation in weight, a higher growth rate and were generally heavier than those raised in groups (South 1982, Gutiérrez et al 2001. However, Hommay et al (2001) commented that contrary to Deroceras reticulatum (Mül-ler 1774) (Stylommatophora: Agriolimacidae) and Limax pseudoflavus Evans, L. valentianus did not reach higher weights when raised in isolation vs. groups.…”