At least one species of clownfish seems to be adapting to life in our increasingly warmer oceans. Spine cheek anemonefish, Premnas biaculeatus, grew up to be bigger and more robust when they were raised in water that’s just a couple of degrees higher than normal, according to new findings published in the Journal of Experimental Marine Biology and Ecology.
In the wild, these anemonefish (also known as maroon clownfish) are usually found living in bulb-tentacle sea anemones in the western Pacific. Jennifer Donelson from the University of Technology Sydney raised juvenile anemonefish at temperatures that are 1.5 degrees Celsius and 3.0 degrees Celsius higher than today’s average temperatures for their habitat. The 3-degree increase is what we expect to happen by the end of this century.
Compared with fish raised in present-day conditions, the fish reared for a year in water that’s plus 3 degrees Celsius were significantly longer, heavier, and in better condition. As New Scientist reports, these fish grew 8% larger and 29% heavier than fish reared at lower temperatures. The elevated temperatures also upped their aerobic metabolism.
Acclimating to future warming may produce overall enhanced performance in some species, the study concludes, though this ability varies substantially between species, even those within the same family. “But at least it won’t be all negative news for all species,” Donelson adds. It’s also unclear whether these bigger, performance-enhanced fish enjoyed higher rates of reproduction.
Recently, we learned that spiny damselfish (Acanthochromis polyacanthus) are able to adjust to warming waters over a few generations. IFLScience reported in July that researchers identified 53 genes that play a part in allowing fish born in warmer environments to thrive compared with their parents and grandparents.