Biomineralization & Shell Morphology in Response to Abiotic Calcium Sources in Cepaea Nemoralis

Abstract

Abiotic sources of minerals are critical for the growth and morphology of various organisms, specifically Cepaea Nemoralis, which integrates environmental calcium into its outer shell. Understanding how environmental sources of minerals influence the development of this animal can help deepen our understanding of the interactions between the environment and the organisms that populate it. Traditional studies of mollusk shell morphology often involve desiccation and separation of the animal from the shell. However, this study improves animal welfare while maintaining accurate determination of growth. In vitro conditions such as humidity, temperature, and light cycles were analogous to natural environments, and a control meal of organic lettuce was provided to each test group. The treatment applied between groups were varying levels of solidified calcium carbonate, which is absorbed in its mineral form by C. Nemoralis. A sample size of 45 snails was used, with all snails randomly divided into five separate treatment groups (nine per group). Over a period of 14 days, each snail’s mass was recorded, which was representative of shell mass. Significant differences were found between the control group and the treatment group of two grams of CaCO₃. The control group expressed a mean growth rate of 0.10 grams over 14 days in comparison to the treatment group, which had a mean growth rate of 0.26 grams, an 160% increase in growth rate. However, the difference in growth rates between treatment groups of increasing levels of substrate was minimal, suggesting that shell growth plateaus at a specific level of calcium consumed.