Variables affecting body burdens of lead, zinc and cadmium in a roadside population of the snailCepaea hortensis M�ller

Abstract

Application of multiple regression analysis to the lead, zinc and cadmium contents of 985Cepaea hortensis collected from a suburban roadside site over two years showed that body weight, age and daylength were the major factors affecting soft tissue body burdens. Other highly significant influences were physiological changes at the juvenile-adult transition, vapour pressure deficit for the two days before sampling, and mean rainfall for the ten days before. Together these factors accounted for 69%, 79% and 87% of the total variance in lead, zinc and cadmium body burdens respectively. Unexplained variance was provisionally ascribed to individual differences in recent diet and digestive activity. The digestive gland contined the majority of the total body burden of each metal and played an important role in lead and zinc elimination. Whereas levels of lead inC. hortensis fluctuated rapidly, zinc was exchanged more slowly, perhaps by active regulation, and cadmium was effectively immobile, accumulating progressively with age. The implications of these results to the predators of land snails, and to terrestrial monitoring programmes, are discussed.

Comparison of the Bioaccumulation Capacities of Copper and Zinc in Two Snail Subspecies (Helix)

“…These authors, working with Helix aspersa Müller, have determined that animals of similar weight and/or height are suitable for the use as biological indicators of metallic pollution. Williamson (1980) has pointed out, for Cepaea nemoralis, that other variables must be considered, such as the photoperiod and the pluviosity, and he has confirmed the importance of the weight and the age of the animals studied. Analysis of the metal content in different species of collected gastropods at wild sites have revealed some differences in accumulation between very close species of slugs (Greville and Morgan, 1989) collected from an old Pb-Zn mine.…”

“…For Zn, small increases in the content and in the concentration according to the dry weight are observed. Williamson (1980), however, in Cepaea, observed only an increase in the content correlated to the body weight [between 0.05 and 0.3 g dry matter (DM), but an opposite relation for the concentration. These divergent results could be connected with the interspecies differences between Helix and Cepaea, but could also arise from the fact that the age of the Cepaea was not precisely known.…”

“…According to the relationship between the size of the snails and the concentration or content of the metal in the animal described by some authors (Coughtrey and Martin, 1977;Williamson, 1980), comparisons of the concentrations and the total contents in each snail at the same age (presented for five H a m fed with D, Figs. 2A and 2B) indicate no clear correlation between these parameters for Cu.…”

Levels of trace metals and effect of body size on metal content and concentration in Arctica islandica L. (Mollusca: Bivalvia) from Kiel Bay, Western Baltic

“…2). Williamson (1980) suggests that the variations in metal content between smaller and larger mussels may be due to the difference in their metabolic activity which may affect the metabolism of metals. However, the contents of Cu and Zn reach a plateau in the larger size group which may indicate that these two essential metals are associated with growth, which also reaches such a plateau in older individuals (Lobel & Wright, 1982).…”

Cd Accumulation and Cd?Metallothionein as a Biomarker in Cepaea hortensis (Helicidae, Pulmonata) from Laboratory Exposure and Metal-polluted Habitats

“…It can be considered, along with other terrestrial molluscs such as some Helicidae and Arionidae, as one of the key species contributing significantly to nutrient and element fluxes in soil ecosystems (Beeby 1985;Dallinger et al, 2001a). C. hortensis is able to accumulate considerable amounts of certain trace elements in its tissues (Williamson, 1980), and can therefore be regarded as a metal ''macroconcentrator'' according to a definition originally formulated by Boha´cˇand Pospı´sˆil (1989) (see Dallinger, 1993). Hence, C. hortensis can serve as a biological indicator of metal accumulation in contaminated soils (Martin and Coughtrey, 1982;Berger and Dallinger, 1993).…”