Abstract
This study evaluated the use of ovarian fluid turbidity as a potential indicator of landlocked fall Chinook Salmon Oncorhynchus tshawytscha egg survival. A total of 21 females were spawned, with nine of the spawns containing between one and ten broken eggs per spawn. Ovarian fluid turbidity ranged from 55.1 to 159 nephelometric turbidity units (NTU), and egg survival to the eyed-stage of egg development ranged from 0 to 68%. There was no significant correlation between ovarian fluid turbidity and egg survival. Mean survival of eggs from the spawns containing broken eggs was 12.3%, which was significantly lower than the 32.9% mean survival from spawns without broken eggs. These results indicate ovarian fluid turbidity cannot be used to predict egg survival in spawns of landlocked fall Chinook Salmon, but the presence of even a small number of broken eggs may be indicative of poor survival to the eyed-egg stage of development.
Highlights
Eggs from landlocked fall Chinook Salmon Oncorhynchus tshawytscha in Lake Oahe, South Dakota, typically exhibit poor, but highly variable, survival during hatchery incubation [1, 2]
Mean survival of eggs from the spawns containing broken eggs was 12.3%, which was significantly lower (P = 0.048) than the 32.9% mean survival from spawns without broken eggs
Negative effects on salmon egg survival from broken eggs were noted by Carl [10] and suggested by Wojtczak et al [6], while Wilcox et al [11] found that egg contents present in the fertilization media reduced fertilization rates in Coho Salmon O. kisutch
Summary
Eggs from landlocked fall Chinook Salmon Oncorhynchus tshawytscha in Lake Oahe, South Dakota, typically exhibit poor, but highly variable, survival during hatchery incubation [1, 2]. Tabrizi et al [7] observed that egg mortality was associated with the turbidity of ovarian fluid mixed with water in the spawns of Caspian Brown Trout Salmotruttacaspius. Turbidity of the ovarian fluid itself, without the addition of water, has not previously been examined as an indicator of egg quality. Quantitative turbidity measurements of ovarian fluid or ovarian fluid mixed with water have not been reported; Tabrizi et al [6] and Wojtczak et al [7] only qualitatively assessed fertilization solution turbidity.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
