Development and evaluation of white bass Morone chrysops genetic resources toward the selective improvement of hybrid striped bass

Authors: Abernathy, Jason; Rawles, Steven - Steve; McEntire, Matthew - Matt

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/2/2019
Publication Date: 2/8/2020
Citation: Abernathy, J.W., Rawles, S.D., McEntire, M.E. 2020. Development and evaluation of white bass Morone chrysops genetic resources toward the selective improvement of hybrid striped bass [abstract]. Aquaculture America 2020, February 9-12, 2020, Honolulu, Hawaii. p. 7.

Interpretive Summary:

Technical Abstract: White bass (Morone chrysops) is a parental species of hybrid striped bass, a fish of increasing commercial importance throughout the US. A chief constraint to the expansion of hybrid striped bass production arises from the use of wild-catch parents in breeding programs. This is costly, unsustainable and leads to uncontrolled variation in the offspring. Our goal is to advance progress in the genetic improvement of hybrids by building additional white bass resources to facilitate selective breeding for agriculturally-important traits. Toward our genomics goal, we created a first-generation white bass genome assembly as well as multiple transcriptome datasets to complement our genome assembly. Improvement of genetic maps and development of molecular markers to discriminate sex, parentage and other critical traits are ongoing. Toward our fish genetics resource goal, wild white bass gathered from Arkansas, Texas and Alabama along with available domesticated strains are being used to establish a base breeding population for familywise evaluations of growth and nutrient utilization on alternative, sustainable diets. To evaluate existing fish stocks and create an even year-class, approximately 100 white bass full-sib families were spawned. Fish were reared in a completely indoor, controlled, bio-secure environment, with larviculture (rotifers and artemia) transitioning to manufactured starter diet. At 247 days post-spawn, white bass were transferred to 250 L tanks (culture depth 100L initial & 200L final based upon fish density) at 1 family/tank and switched to a custom fishmeal free (FMF) diet. Mixed family controls (n=4 tanks each) were evaluated simultaneously and fed either the custom FMF diet or a commercial control diet (45/16% protein/lipid) diet. Fish were fed to apparent satiation once daily. Gains were evaluated over a seven-month period. Distinct differences in growth performance was observed among wild and domestic populations. Wild (male) x domestic (female) cross families performed significantly better when fed a fishmeal free diet then did their reciprocal crosses, and to a similar degree as that of pure domesticated white bass and those fed a control diet. Pure wild cross families had the worst growth performance during this evaluation period. Top performers from each family were selected for propagation. The combination of these resources substantially expands the genetic toolbox for white bass, while the application toward white bass breeding will aid in its improvement through selective breeding. Progress on white bass resources will be presented and discussed.