Abstract
Ventridens demissus is one of over 2,000 species of land snail in the United States and Canada. Like other zonitid snails, the species is small (10 mm in width) with a thin shell; its distribution ranges from the Appalachians to the southwestern Gulf Coast. Like many land snails, little is known about the biology of V. demissus, and its conservation status remains unstudied. Using a population from Seabrook, Texas, the morphology, reproductive behavior, and gut microbes of V. demissus were described in order to broaden the understanding of this land snail species' life history. Shell morphology data were consistent with those reported previously, while the mean shell required 4.6 N to crush. Reproductive behavior was witnessed between a single pair of individuals, who simultaneously probed one another with their dart apparatuses. In the laboratory, V. demissus laid over 300 small (1.5 mm) eggs, and the growth of twenty hatchlings was followed for at least ten weeks. Gut microbes were dominated by Mycoplasma, Paenibacillus, and enteric groups. These data fill in existing gaps regarding the biology of V. demissus. Future studies on the species should include additional populations from across its range, controlled breeding and rearing experiments, and finer-scaled microbial analysis to distinguish between natural gut flora and ingested microbes.
Sex-specific predation risk and the evolution of sexual dimorphism in immunocompetence: a theoretical analysis
