TY - JOUR
T1 - The effect of warming on mortality, metabolic rate, heat-shock protein response and gonad growth in thermally acclimated sea urchins (Heliocidaris erythrogramma)
AU - Harianto, Januar
AU - Nguyen, Hong Dao
AU - Holmes, Sebastian P.
AU - Byrne, Maria
PY - 2018
Y1 - 2018
N2 - Environmental temperature affects the physiology and fitness of ectotherms, an important consideration in a warming ocean. We investigated the effects of acclimation to increased temperature in the Australian sea urchin, Heliocidaris erythrogramma. After a gradual introduction to increasing temperature (1 °C 6 day−1), sea urchins were held for ~ 3 months in four treatments at three elevated temperatures (22, 24 and 26 °C) and the median annual temperature, 20 °C. The effect of elevated temperature on survival, metabolic rate, Q10, heat-shock protein (HSP70) expression, gonad index and gonad histology were examined. There was no detectable effect of temperature on metabolic rate for the 22 and 24 °C treatments, although survival decreased by 23% in the 24 °C treatment and there was an increase in mean HSP70 expression. At 26 °C, metabolic rate was lower than at 22 and 24 °C, but was similar to controls, indicating that metabolic depression may have occurred, whereas survival decreased by 31% and HSP70 expression increased threefold. It is clear that there is an active physiological response in urchins held at the highest temperatures. The deleterious effect of living at temperatures projected for the future indicates that the persistence of future populations of H. erythrogramma will depend on acclimation as habitat warming continues.
AB - Environmental temperature affects the physiology and fitness of ectotherms, an important consideration in a warming ocean. We investigated the effects of acclimation to increased temperature in the Australian sea urchin, Heliocidaris erythrogramma. After a gradual introduction to increasing temperature (1 °C 6 day−1), sea urchins were held for ~ 3 months in four treatments at three elevated temperatures (22, 24 and 26 °C) and the median annual temperature, 20 °C. The effect of elevated temperature on survival, metabolic rate, Q10, heat-shock protein (HSP70) expression, gonad index and gonad histology were examined. There was no detectable effect of temperature on metabolic rate for the 22 and 24 °C treatments, although survival decreased by 23% in the 24 °C treatment and there was an increase in mean HSP70 expression. At 26 °C, metabolic rate was lower than at 22 and 24 °C, but was similar to controls, indicating that metabolic depression may have occurred, whereas survival decreased by 31% and HSP70 expression increased threefold. It is clear that there is an active physiological response in urchins held at the highest temperatures. The deleterious effect of living at temperatures projected for the future indicates that the persistence of future populations of H. erythrogramma will depend on acclimation as habitat warming continues.
KW - ocean temperature
KW - sea urchins
UR - http://handle.westernsydney.edu.au:8081/1959.7/uws:46589
U2 - 10.1007/s00227-018-3353-8
DO - 10.1007/s00227-018-3353-8
M3 - Article
SN - 0025-3162
VL - 165
JO - Marine Biology
JF - Marine Biology
IS - 6
M1 - 96
ER -