EAPSI: Understanding Biological Invasion of Asian Carps Involving Hybridization

Gaughan Sarah J, Omaha NE

Investigators

Abstract

Bighead carp (Hypophthalmichthys nobilis) and silver carp (H. molitrix), both native to China, are invasive species in the US. Natural hybridization occurs extensively between these two species in the Mississippi River Basin; however hybridization has long been considered rare in the Yangtze River (YR). The effect of hybridization on fitness or invasion potential remains unknown. The recent construction of Three Gorges reservoir has caused dramatic environmental change in native regions, and may facilitate hybridization. The objectives of this project are 1) to obtain a better understanding about ecological factors that pertain to Asian carp hybridization and 2) to evaluate the fitness of F1 hybrids farmed in aquaculture ponds. Environmental and morphological data, along with tissue samples (genetic assay), will be collected from fish caught in the middle and upper reaches of the YR, in collaboration with scientists from Shanghai Ocean University and the Institute of Hydroecology (Wuhan), Ministry of Water Resources & Chinese Academy of Sciences. The results are expected to improve our understanding of the hybridization mechanisms, which will benefit the management and control of invasive Asian carps in the US. This project employs a novel approach to integrate genomic, morphological and ecological information into an important knowledge base to explore the detrimental factors linked to Asian Carp invasions in the U.S. The results from this proposed research are likely to provide an explanation of why F1 hybrids are less prevalent in introduced habitats in the Mississippi River Basin (MRB). The comparison between native and invasive Asian carps in morphology and genomics will allow us to identify adaptive characters, which will provide a better understanding of the invasiveness of the Asian carps. The investigation of habitat uses by Asian carps in both native and invasive environments will allow us to determine environmental conditions which promote hybridization and invasion. Understanding the relative roles of biology and genomics of exotic species, environmental attributes, and evolutionary events would transform the knowledge of invasion biology. This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Ministry of Science and Technology of China.