Brittle arms lose muscle

In the future, sea creatures may pay to build with calcium carbonate

Brittle stars may end up with less star power as greenhouse gases change ocean chemistry.

SPINDLY STAR One of the long, wavy arms of an Amphiura filiformis brittle star has recently regrown its end, which now looks pale. H. L. Wood

As human activity increases concentrations of carbon dioxide in the air, ocean chemistry is changing, says Hannah L.