COA Grant Summary (2018 award) for: morphometrics and phylogeography of the cave-obligate land snail Helicodiscus barri (Gastropoda, Stylommatophora, Helicodiscidae)

摘要

Many phylogeographic studies have recently led to the detection of many species complexes within morphologically ambiguous species formerly undescribed by the scientific community (here defined as cryptic species). Organisms such as land snails are at a particularly higher risk of species misinterpretation, in that gastropod systematics are based almost entirely on external shell morphology. Several land snail species obligately inhabit caves and other subterranean habitats. These snails, such as the troglobitic Helicodiscus barri Hubricht, 1962, may often exhibit mosaic, disjunct geographic distributions, which may indicate the presence of cryptic diversity. Subterranean ecosystems are associated with especially high degrees of cryptic speciation, largely owing to the abiotic similarities of these systems. Characterized by geographic isolation and relatively simple biological communities, caves are often viewed as analogous to oceanic islands. Strong selective pressures and the isolation of subterranean ecosystems result in morphological stasis among otherwise genetically distinct species, largely due to the parallel evolution of these lineages.