Daily, repeating fluctuations in embryonic incubation temperature alter metabolism and growth of Lake whitefish (Coregonus clupeaformis).
Comp Biochem Physiol A Mol Integr Physiol
; 226: 49-56, 2018 12.
Article
in En
| MEDLINE
| ID: mdl-30114471
ABSTRACT
Lake whitefish (Coregonus clupeaformis) utilize overwintering embryonic development (up to 180â¯days), and such stenothermic, cold-water embryos may be particularly susceptible to thermal shifts. We incubated whitefish embryos in temperature treatments that were constant temperature (2.0⯱â¯0.1⯰C, 5.0⯱â¯0.1⯰C, and 8.0⯱â¯0.1⯰C; mean⯱â¯SD) or variable temperature (VT, meanâ¯=â¯5.0⯱â¯0.3⯰C). In the VT, a daily 2⯰C temperature change followed a continuous pattern throughout development 2-4-6-8-6-4-2⯰C. Hatchling survival proportion from fertilization to hatch was significantly impacted by incubation temperature (Pâ¯<â¯0.001) 2⯰C (0.88⯱â¯0.01) and 5⯰C (0.91⯱â¯0.01) showed higher survival than both the VT (0.83⯱â¯0.02) and 8⯰C groups (0.15⯱â¯0.06), which were statistically distinct from each other. Time to hatch (dpf) was significantly different across all treatments (Pâ¯<â¯0.001) 8⯰C (68⯱â¯2â¯dpf), VT (111⯱â¯4â¯dpf), 5⯰C (116⯱â¯4â¯dpf), 2⯰C (170⯱â¯3â¯dpf). Likewise, hatchling yolk-free dry mass (mg) and total body length (mm) were significantly different across all treatments (Pâ¯<â¯0.001) 8⯰C (0.66⯱â¯0.08â¯mg; 11.1⯱â¯0.08â¯mm), VT (0.97⯱â¯0.06â¯mg; 11.7⯱â¯0.05â¯mm), 5⯰C (1.07⯱â¯0.03â¯mg; 12.0⯱â¯0.02â¯mm), 2⯰C (1.36⯱â¯0.04â¯mg; 12.8⯱â¯0.05â¯mm). Oxygen consumption rate (VÌo2) was significantly affected by the interaction between treatment and measurement temperature (Pâ¯<â¯0.001). Hatchling VT whitefish showed mean VÌo2 that was higher compared to the 2⯰C group measured at 2⯰C, and lower compared to the 2⯰C and 5⯰C group measured at 8⯰C. This study demonstrates that the VT incubation treatment produced fewer (increased mortality), smaller embryos that hatched earlier than 2⯰C and 5⯰C embryos. The plasticity of VÌo2 for this stenothermic-incubating fish species under variable incubation conditions reveals a metabolic cost to cycling thermal incubation conditions.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Salmonidae
Limits:
Animals
Language:
En
Journal:
Comp Biochem Physiol A Mol Integr Physiol
Journal subject:
BIOLOGIA MOLECULAR
/
FISIOLOGIA
Year:
2018
Document type:
Article