Locomotor responses to salt stress in native and invasive mud‐tidal gastropod populations (Batillaria)

• Published in: Ecology and evolution Vol. 11; no. 1; pp. 458 - 470
• Main Authors: Ho, Phuong‐Thao, Nguyen, Hoa Quynh, Kern, Elizabeth M. A., Won, Yong‐Jin
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01-01-2021; John Wiley and Sons Inc; Wiley
• Subjects: Abiotic stress; adaptive divergence; Aquatic habitats; Batillaria attramentaria; Behavior; Divergence; Evolution & development; Experiments; Exposure; Gastropoda; Geographical distribution; invasive species; Laboratories; Locomotion; Locomotor activity; Mathematical models; Mitochondria; Mollusks; Original Research; Phylogeny; Population; Populations; Saline water; Salinity; Salinity effects; Salinity tolerance; Salt tolerance; Shores; snail behavior; Snails; Statistical models; Stress; South Korea; California; Monterey Bay; United States > US; Japan; salinity; adaptive divergence; snail behavior; invasive species; locomotion
• ISSN: 2045-7758; 2045-7758
• DOI: 10.1002/ece3.7065

Plasticity in salt tolerance can be crucial for successful biological invasions of novel habitats by marine gastropods. The intertidal snail Batillaria attramentaria, which is native to East Asia but invaded the western shores of North America from Japan 80 years ago, provides an opportunity to examine how environmental salinity may shape behavioral and morphological traits. In this study, we compared the movement distance of four B. attramentaria populations from native (Korea and Japan) and introduced (United States) habitats under various salinity levels (13, 23, 33, and 43 PSU) during 30 days of exposure in the lab. We sequenced a partial mitochondrial CO1 gene to infer phylogenetic relationships among populations and confirmed two divergent mitochondrial lineages constituting our sample sets. Using a statistical model‐selection approach, we investigated the effects of geographic distribution and genetic composition on locomotor performance in response to salt stress. Snails exposed to acute low salinity (13 PSU) reduced their locomotion and were unable to perform at their normal level (the moving pace of snails exposed to 33 PSU). We did not detect any meaningful differences in locomotor response to salt stress between the two genetic lineages or between the native snails (Japan vs. Korea populations), but we found significant locomotor differences between the native and introduced groups (Japan or Korea vs. the United States). We suggest that the greater magnitude of tidal salinity fluctuation at the US location may have influenced locomotor responses to salt stress in introduced snails.
We studied the effect of geographic distribution and genetic composition of the tidal gastropod Batillaria attramentaria on kinetic responses to varying levels of salt stress. We found that the snail population that had entered the United States from East Asia, which took 80 years to adjust to the new osmotic environment, had a shorter travel distance than the native populations. This suggests that the locomotive trait of invasive snails may have rapidly evolved due to the different tidal salinity in the new habitat.