1a.Objectives (from AD-416)
The yellow perch (Perca flavescens) is an important social and economic species in the Great Lakes; however, populations have plummeted. Given strong consumer demand, and high fillet value ($12.00/lb.- $15.00/lb retail), there is an urgent need to develop a sustainable yellow perch aquaculture industry that can deliver a high-quality cultivar year-round. Due to strong consumer demand, research efforts will focus on improving yellow perch production using state-of-the-art genetic and physiological techniques. Our long-term goal is to produce a genetically defined broodstock of yellow perch that will enable development of superior germplasm for release to stakeholders. Initial efforts for this project plan have yielded genetic information on genetic structure among various U.S. perch populations, and have identified new genes and genetic sequences that have been used to.
1)direct genetic selection to improve cultivar traits, and.
2)be used for pedigree tracking to further improve/support future selective breeding efforts. The new technologies and resources that are developed from this program will continue to support innovation and improvement in perch aquaculture.

1b.Approach (from AD-416)
Progress on the broodstock program has exceeded expectations and our anticipated time-line. Our ARS cooperators are now examining the progeny from these initial crosses for growth performance. The progeny from the parental crosses within each strain are separating out into different size classes. Consequently, it will be necessary to cross top performers from each strain to produce an F2 generation that should exhibit enhanced growth. In addition to selecting for desired traits, maintaining genetic diversity, and avoiding inbreeding, we have other prioritized tasks. To address this, a subset of individuals within each strain will be analyzed (using microsatellites) to determine parentage. Parentage analysis will also allow us to determine the originating strain and specific crosses (parents) that resulted in desired traits in the F1 progeny.

3.Progress Report
Out-of-Cycle Spawning: Photothermal regimes are being used to develop out-of-cycle spawning in yellow perch broodstocks. Gametes were collected & artificially fertilized from wild broodstock of the Choptank River (MD) in 3/2007. The F1 generation was photothermally manipulated to become a July spawning broodstock. A similar approach was used to develop a January spawning broodstock with fish collected from the Sassafras River (MD) starting in 3/2003. Fingerlings produced from this Jan spawning strain were phothermally manipulated to become an Oct spawning broodstock. In 2007, these fish produced 11 million eggs, resulting in a F3 generation. A review of the history of this F3 generation: P1s were wild March spawners, F1s were captive Jan spawners, & F2s were captive Oct 2007 spawners. These F3 generation perch were evaluated for critical developmental traits. Yellow Perch Broodstock Development: Yellow perch progeny from pair crosses of wild perch broodstocks from the Perquimans River (NC), Choptank River (MD), and Lake Winnebago (WI) were evaluated for growth performance over 12 months. Fish were assayed for length & weight bimonthly. Final average weight was: Perquimans River fish, 138.12 g; Choptank River fish, 126.70 g; & Winnebago fish, 52.08 g. Final lengths, weights & absolute growth rates were not significantly different between Choptank & Perquimans fish, but both groups were significantly larger than the Winnebago fish. Condition factors were also different. Choptank fish had the highest condition factor, followed by Perquimans & then Winnebago fish. The top 25-35% performers for each strain are now being pit-tagged, genotyped & placed under photoperiod & temperature regimes to cycle them for spawning next spring (2009) to produce the F2 generation. Expressed Sequence Tag (EST) Development: cDNA libraries were constructed for livers & brains of yellow perch treated (and controls) with dietary 17-beta-estradiol (E2). From each of the 4 libraries, 4,000 ESTs were obtained & analyzed (16,000 total). These libraries were analyzed to determine genes that were up- & downregulated with E2 treatment. From the liver, we found 13 genes to be higher in the control versus E2 fish, & 11 higher in estrogen compared to controls. In the brain, we found 9 genes elevated in controls above E2-treated fish, & 11 higher in E2 versus controls. Quantitative PCR (QPCR) assays were developed to measure these genes, & are nearly complete for the liver. Data so far supports their differential regulation as determined by bioinformatic analysis. More ESTs (8,000) were obtained from ovary cDNA libraries from perch stimulated with human chorionic gonadotropin & progestational steroids. More recently, a cDNA library was constructed from 2-day-old yellow perch larvae; sequencing of that library has begun. All ESTs are being mined for microsatellites & genes of interest. Monitoring of this SCA includes almost daily interaction between the ARS SY and SCA personnel, e-mails, semi-annual reports, & attendance at regional meetings.