In-Hatchery and in-River Monitoring of Spontaneous Autopolyploidy in Kootenai River White Sturgeon

A goal of the Kootenai Tribe of Idaho Native Fish Conservation Aquaculture Program (KTOI-NFCAP) is to preserve the remaining genetic diversity of the endangered Kootenai River White Sturgeon population.  The Kootenai Tribe has been producing and releasing year-classes annually since 1999 to offset poor natural recruitment.   Genetic diversity monitoring and parentage analyses have been an integral part of the White Sturgeon program.  More recently, monitoring was expanded to examine families for spontaneous autopolyploidy (SA).  Drauch-Schreier et al. (2011; 2012; 2013) revealed spontaneous autopolyploid White Sturgeon have been unintentionally produced by the KTOI-NFCAP during 2011-2014, and likely during years past.  A spontaneous autopolyploid is an individual with a larger than normal genome size.  A wild-type White Sturgeon is an ancient octoploid (8N) with ~250 chromosomes; whereas, SA individuals are dodecaploid (12N) and may produce decaploid (10N) offspring after a mating with a normal 8N individual (Drauch-Schreier et al. 2011).  The overall number of SA (12N) juveniles per year class from 2011-2014 has been consistent (8.5 – 11.5%); however, SA in full-sibling families ranges from 0-87% (most families are 0%).  This presentation will provide an overview and results of the Kootenai River White Sturgeon in-hatchery and in-river monitoring of spontaneous autopolyploidy.