Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Population dynamics of the non-native freshwater gastropod, Cipangopaludina chinensis (Viviparidae): a capture-mark-recapture study.

Abstract

Capture-mark-recapture (CMR) is commonly used in conservation biology, but rarely used to study non-native species in freshwater habitats. The power of CMR lies in the ability to go beyond simple density estimates and to quantify invasion dynamics and vital population parameters. I applied CMR to a population of the non-native Chinese mystery snail (Cipangopaludina chinensis, Viviparidae) in a 1.46 ha pond on Long Island, NY to estimate population size and survival probability in the waterbody and to uncover potential mechanisms for enormous differences in introduction success within and between waterbodies (observed densities range <1-40 individuals m-2). The C. chinensis population increased from approximately 150 to nearly 970 individuals from 2010 to 2012. Daily capture probabilities were low (<0.2) for snails of all sizes. Daily survival probabilities were size-dependent (almost 1.0 for snails larger than 30 mm shell length, and decreasing below that threshold), suggesting size-dependent mortality. This study highlights the ease of applying CMR to C. chinensis and its potential for other non-native species. Traditional survey methods such as density estimates with transects or quadrats cannot document increasing population sizes or size-specific mortality factors, which are essential for understanding introduction success and dynamics.