Every bug is sacred: Management of highly diversified Abedus populations

Authors: David* Lytle, Emily Hartfield-Kirk

Year: 2015 (xlvii)

Abstract

Giant water bugs in the genus Abedus are found in streams and rivers throughout the deserts of southern Arizona, southern California, and Mexico. They serve an ecological role as top predator in many fishless streams, and can also be predators on fish and anurans. We present new data from whole genome sequencing (2bRAD) of Abedus herberti that suggests populations are highly isolated from one another across the landscape, and might better be considered a species flock of unique lineages rather than a homogenous single species. These data are congruent with previous mtDNA and microsatellite studies that pointed to high levels of among-population divergence. High genetic divergence among populations also explains the rich diversity of behavior (flood escape behavior) and morphology (extreme variation in body size) that is observed across Abedus populations. These patterns present unique challenges for the management of desert streams. First, the high degree of endemism suggests that translocating individuals among drainages, and even within drainages, could be problematic. Second, loss of populations, as has been documented in several Arizona streams, likely represents the loss of unique evolutionary heritage.