Sealife thrives in hot and cold water

The temperature a fish experiences at the earliest stage of development can affect how it copes with temperature changes later in life, new research suggests.

Researchers found that zebrafish embryos incubated in water warmer or cooler than average coped better with variation as adults.

The fish could swim faster andhad muscle better suited for aerobic exercise than fish whose embryos were incubated at average temperatures.

The study suggests that being exposed to challenging temperatures in early life might help some fish cope with warmer or more variable temperatures when they get older, which could help mitigate the adverse effects of global warming.

It was carried out by professor Ian Johnston and Graham Scott at the University of St Andrews.

Prof. Johnston said: “This research represents a paradigm shift in our understanding of the thermal biology of aquatic organisms.

“It shows how the temperature experienced at the earliest stages of development can have persistent effects on the physiology of adult stages.

“In order to predict the likely effects of future climate change, these early developmental effects certainly need to be taken into account.

“Indeed, for some species, warming at the embryo stage may improve the ability of adults to cope with seasonal temperature change later on in life.”

Zebrafish were selected as a model fish species which is widely usedin fundamental biological and biomedical research.

Embryos were split into three groups by the researchers. Some incubated at the control temperature of 27°C while others were incubated near the extremes for development, at 22°C and at 31°C. When they hatched, they were all raised under common conditions at 27°C.