Landlocked Fall Chinook Salmon Maternal Liver and Egg Thiamine Levels in Relation to Reproductive Characteristics

Abstract

Object:Landlocked fall Chinook Salmon Oncorhynchus tshawytscha in Lake Oahe, South Dakota, typically experience poor reproductive success. Introduction:

The Relationship Between Digital Egg Coloration and Egg Survival in Landlocked Fall Chinook

“…The significant difference in a* values between those spawns which experienced total mortality versus those where at least some of the eggs survived is of particularly interest. Doyle et al (2017) reported lower egg thiamine levels in landlocked fall Chinook salmon spawns which did not survive. Huysman et al (2018) observed that female salmon producing completely non-viable spawns may have been held for a slightly longer period of time prior to spawning, and that their spawns had relatively fewer eggs.…”

“…The positive correlation between egg coloration values and survival, as well as the significantly greater a* (red) values in spawns which experienced at least some egg survival, may be temperature related. Chinook salmon in Lake Oahe experience elevated temperatures during egg development and maturation (Young et al, 2016;Doyle et al, 2017). In addition, spawning water temperatures are frequently above 15°C.…”

“…The egg survival values observed during the multiple years of this study were typical of Lake Oahe Chinook salmon eggs (Barnes et al, 2000;Young et al, 2016). This poor survival has been attributed to nutritional limitations, elevated spawning water temperatures, and genetic issues (Young et al, 2016;Doyle et al, 2017). The significant difference in a* values between those spawns which experienced total mortality versus those where at least some of the eggs survived is of particularly interest.…”