Range reduction of Oblong Rocksnail, Leptoxis compacta , shapes riverscape genetic patterns

PeerJ

article

Aaliyah D. Wright¹  Nicole L. Garrison²  Ashantye’ S. Williams⁴  Paul D. Johnson⁵  Nathan V. Whelan² 

[1] Tuskegee University;School of Fisheries, Aquaculture, and Aquatic Sciences, College of Agriculture, Auburn University;Department of Natural Resources and Mathematics, West Liberty University;Southeast Conservation Genetics Lab, Warm Springs Fish Technology Center;Alabama Aquatic Biodiversity Center, Alabama Department of Conservation and Natural Resources

关键词: Pleuroceridae;    Conservation genomics;    Cahaba River;    Alabama;    Narrow-range endemic;    Water quality;    Habitat suitability;    Wahlund effect;    Gastropoda;    Freshwater snails;   

DOI  :  10.7717/peerj.9789

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

Many freshwater gastropod species face extinction, including 79% of species in the family Pleuroceridae. The Oblong Rocksnail, Leptoxis compacta, is a narrow range endemic pleurocerid from the Cahaba River basin in central Alabama that has seen rapid range contraction in the last 100 years. Such a decline is expected to negatively affect genetic diversity in the species. However, precise patterns of genetic variation and gene flow across the restricted range of L. compacta are unknown. This lack of information limits our understanding of human impacts on the Cahaba River system and Pleuroceridae. Here, we show that L. compacta has likely seen a species-wide decline in genetic diversity, but remaining populations have relatively high genetic diversity. We also report a contemporary range extension compared to the last published survey. Our findings indicate that historical range contraction has resulted in the absence of common genetic patterns seen in many riverine taxa like isolation by distance as the small distribution of L. compacta allows for relatively unrestricted gene flow across its remaining range despite limited dispersal abilities. Two collection sites had higher genetic diversity than others, and broodstock sites for future captive propagation and reintroduction efforts should utilize sites identified here as having the highest genetic diversity. Broadly, our results support the hypothesis that range contraction will result in the reduction of species-wide genetic diversity, and common riverscape genetic patterns cannot be assumed to be present in species facing extinction risk.

【 授权许可】

CC BY