Initial investigations into the production of triploid sunshine bass using temperature shock

Authors: Straus, David - Dave; Abernathy, Jason; KELLY, ANITA - Auburn University; QUINTERO, HERBERT - The Ohio State University; FREEZE, T. MIKE - Keo Fish Farm; WILLIAMS, RICK - Keo Fish Farm

Submitted to: North American Journal of Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/15/2023
Publication Date: 2/9/2024
Citation: Straus, D.L., Abernathy, J.W., Kelly, A.M., Quintero, H.E., Freeze, T., Williams, R.S. 2024. Initial investigations into the production of triploid sunshine bass using temperature shock. North American Journal of Aquaculture. 86:234-241. https://doi.org/10.1002/naaq.10329.
DOI: https://doi.org/10.1002/naaq.10329

Interpretive Summary: This study was intended to develop a protocol to produce sterile (aka triploid) sunshine bass, also known as hybrid striped bass. Sterile fish are desired because egg production by females can cause economic losses in aquaculture. Temperature shock (3 warm and 3 cold temperatures at several times after fertilization) on freshly fertilized eggs was used to do this in a small-scale study. We found the best cold and warm combination and then did a full-scale, commercial production of larvae and grew them in ponds for 30 days. We only found 15 fish in the pond from the cold-treated eggs, and none of them were triploid. There were more survivors in the warm-treated eggs and testing 50 survivors indicated 14% were triploid. This study demonstrated that warm temperature shock was better than cold shock to induce a greater percentage triploid (aka sterile) sunshine bass.

Technical Abstract: Sunshine bass are an important food fish raised in U.S. aquaculture. Spawning is performed by manual stripping and fertilizing female white bass (Morone chrysops) eggs with male striped bass (M. saxatilis) sperm; embryos hatch in approximately 48 hours. Mature sunshine bass females can become fertile and produce eggs, which is problematic in commercial food production; therefore, triploid fish are desired. The present study incorporated three warm and three cold temperature shocks, along with three post-fertilization initiation times and three exposure times for each temperature during initial stages of incubation to induce triploidy. After exposure to temperature shocks, eggs were incubated in experimental hatching systems. The best performing cold and warm temperatures and times (and an ambient diploid control) were then used to incubate embryos using commercial practices from a single batch of eggs. Larvae were stocked at approximately 75,000 larvae/acre in freshly filled and fertilized ponds. Fry were sampled weekly and harvested at 30 days. There were 15 survivors from the cold-treated triploid pond; these were tested via Coulter Counter, and none were triploid. Testing 50 survivors from the warm-treated triploid pond indicated 14% were triploid. Therefore, initial trials indicated that warm temperature shock was preferrable to cold shock to induce a greater percentage triploid sunshine bass.