Despite the importance of understanding the mechanisms underlying range limits and abundance structure, few studies have sought to do so. Here we use a terrestrial slug species, Deroceras panormitanum, that has invaded a remote, largely predator-free, Southern Ocean island as a model system to do so. Across Marion Island, slug density does not conform to an abundant centre distribution. Rather,...

The nutritional requirements of Streptothrix corallinus (Nocardia corallina, Breed et al., 1948) were studied by Reader (1928) who showed that growth in a medium containing glucose, ammonium sulfate and inorganic salts was stimulated by the addition of small amounts of tryptic meat broth or yeast extracts. The active principle in these additions was thought to be related to, but not identical w...

Terrestrial gastropods were collected from wetland, grassland, and forested habitats throughout eastern and southcentral South Dakota from May-August of 1999 and 2000 to assess the role of gastropods in transmission of meningeal worm (Parelaphostrongylus tenuis) to white-tailed deer (Odocoileus virginianus) populations throughout the state. A total of 4,063 gastropods representing 14 species, f...

Morphological and morphometric aspects of larval development of Umingmakstrongylus pallikuukensis in Deroceras laeve and the effects of temperature on development rates in D. laeve and Deroceras reticulatum were investigated in the laboratory. Larval stages were best differentiated by separation of cuticular sheaths, tail structure, and viability following digestion. Growth in body and esophagu...

Parelaphostrongylus odocoilei is a protostrongylid parasite that has recently been recognized at several locations in sub-Arctic, but not Arctic, North America. We investigated factors that may determine the distribution of P. odocoilei, including suitable gastropod intermediate hosts, temperature requirements for larval development in gastropods, and larval emergence facilitating overwinter tr...

In Deroceras reticulatum, mucus cell ultrastructure and the histochemistry of the epidermis and the digestive tract epithelia were shown to be influenced by carbamate and metaldehyde, two molluscicides used as both contact and oral toxins. After carbamate poisoning mucus production is increased and the chemical composition of the slime is modified. Ultrastructural damage is less intense than af...