Ploidy Determination of Grass Carp and Black Carp Captured from the Great Lakes Basin (USA and Canada) and Other Watersheds

A USGS-developed technique for determining ploidy of post-mortem Asian carp using flow cytometric analysis has been applied in a USFWS program to help managers assess the threat of grass carp Ctenopharyngodon idella and black carp Mylopharyngodon piceus establishment in the Great Lakes Basin and other waters where these species were not previously known to exist. Since January 2013, samples from 42 grass carp and 12 black carp were collected by partners representing a five-fold rate of sample analyses from previous years by virtue of this FWS-dedicated program. Samples were shipped according to standard protocols. Analyses were conducted at USFWS Whitney Genetics Laboratory, Onalaska, WI. Of the 54 individual samples analyzed, 32 (8 black carp) were diploid, and 17 (0 black carp) were triploid. Ploidy status of the remaining samples was not determined due to sample degradation resulting from deviation from protocols. Results were provided to partner agencies and mapped by USGS Nonindigenous Aquatic Species Program allowing searchable results (http://nas.er.usgs.gov/Default.aspx) and alerts for the public. Ploidy results, in conjunction with collection data and environmental parameters can help managers decide if carp are actively reproducing in self-sustaining populations and what management actions, if any, should be applied for control or eradication.