Effects of Fixed and Fluctuating Temperature on Hatch of Round Whitefish and Lake Whitefish Eggs

Abstract

Temperature‐response information for use in evaluating thermal discharges is often over 30 years old and in the nonpeer‐reviewed literature, especially for Round Whitefish Prosopium cylindraceum and Lake Whitefish Coregonus clupeaformis exposed to nonlethal, elevated, and variable temperatures. Egg incubation experiments on Round Whitefish collected in Lake Ontario and Lake Whitefish collected in Lake Huron were carried out from December 13, 2011, to April 7, 2012. Experimental treatments included ambient baseline control conditions as well as fixed and fluctuating (variable) temperature increases of 1, 2, 3, and 5°C above ambient baseline conditions. For both species, the window for hatching for all experimental temperature treatments was variable (range, 10–38 d for Round Whitefish and 11–44 d for Lake Whitefish), and the hatching windows tended to be greater as temperatures increased. Our results indicated that both fixed and variable incremental increases in temperature above ambient baseline conditions have a statistically significant effect on 50% hatch, and hatch occurs earlier with higher incremental temperature increases. The ecological significance of advanced hatch, such as indirect mortality and food source availability, was evaluated. Received February 19, 2013; accepted July 8, 2013

Impacts of temperature, morpholine, and chronic radiation on the embryonic development of round whitefish (Prosopium cylindraceum)

“…Both lake and round whitefish embryos from constant temperature regimes had delayed median hatch, likely caused by the lack of warming periods near the end of development (Patrick et al ; Thome et al ; Lim et al ; present study). In agreement with Patrick et al (), round whitefish embryos reared with faster (2 °C/wk) warming periods reached median hatch relatively more quickly (Table ), with smaller hatch windows (Supplemental Data, Table S3), compared with embryos reared with slower warming (1 °C/wk S A embryos from our study). Interestingly, faster warming rates not only influenced hatch timing, but also consistently increased mortality post hatch (S B , S B +SP A , and S B +SP B regimes; Supplemental Data, Table S4).…”

“…The maximum temperature of 15 8C was chosen because it is roughly in between hatching and summer temperatures (Armstrong et al 1977). Although more representative of a very warm spring compared with previous studies (Griffths, 1980;Patrick et al 2013;Thome et al 2016), the rapid warming used in the present study allowed for larvae to quickly reach temperatures where they displayed foraging/feeding behaviors. Beginning at 5 to 10 dph (based on visual inspection of yolk sac size and foraging behavior), larvae were fed crushed fish pellets (Otohime Larval Fish Diet; Marubeni Nisshin Feed) every 2 to 3 d, followed 1 h later by 100% water change.…”

The influence of ontogeny and prey abundance on feeding ecology of age‐0 Lake Whitefish (Coregonus clupeaformis) in southeastern Lake Michigan

“…Water temperatures in 2014 were much colder and the initial appearance of Lake Whitefish was later than during other years, but temperatures warmed up quickly compared with other years. An advanced hatch due to early warming can lead to a mismatch with prey for Lake Whitefish (Patrick et al, 2013), which may have occurred during 2015-2017 compared with 2014, when a late hatch coincided with high zooplankton abundance as water temperatures warmed up quickly. An advanced hatch due to early warming can lead to a mismatch with prey for Lake Whitefish (Patrick et al, 2013), which may have occurred during 2015-2017 compared with 2014, when a late hatch coincided with high zooplankton abundance as water temperatures warmed up quickly.…”

Is There a Trade-Off between Radiation-Stimulated Growth and Metabolic Efficiency?

“…This later possibility is an example of phenological mismatch (38, 39) which has been identified as a specific concern for lake whitefish (27).…”

“…Embryonic development in fish also offers a suitable life-stage for examining metabolic effects of ionizing radiation because growth takes place under comparatively simple bioenergetic conditions where nutrition is supplied endogenously, active metabolism is minimal, and factors such as water quality, and oxygen availability may be controlled with reasonable accuracy in a laboratory setting. The lake whitefish offers further advantages as a test organism due to its low intraclutch variability in egg size (25), and lengthy development (26)(27)(28)(29), which allows for the accurate targeting of specific developmental stages as well as enabling manual dechorionation and measurements to be completed at a consistent point in development.…”