Tiny Jewels: An introduction to pupillid taxonomy,ecology, and collection

摘要

Across most of North America roughly 50% of all land snail species and almost 90% of all individuals are less than 5mm in maximum dimension, or approximately the size of Lincoln's chin on a penny (Fig. 1). Of these, the Pupillidae make an especially important contribution to biodiversity. This family (here used in the expansive, historical sense as outlined by H.A. Pilsbry) includes the genera Bothriopupa, Chaenaxis, Columella, Gastrocopta,Pupilla, Pupisoma, Sterkia, and Vertigo, and encompasses almost 10% of the entire USA and Canadian fauna (-125 species), with an unknown number of additional taxa residing in Mexico. North America represents the global biodiversity center for Chaenaxis,Gastrocopta, Pupilla, and Vertigo, harboring at least 2/3 of all known global taxa and all known morphological groups. The Pupillidae are the third most diverse family east of the continental divide (12% of the total fauna), exceeded only by the Polygyridae (30%) and Zonitidae (22%). Pupillids alone make up approximately one-third of both total species diversity and number of individuals for site-scale faunas throughout North America, with this level approaching 80% - 100% within the northern taiga and tundra, acidic wetlands and savannas of the southeastern coastal plain, and fogbelt chaparral of the California coast. In some places, such as the pocosins of the North Carolina coastal plain, the number of pupillid land snails can exceed 5,000 individuals per square meter.