can I bend your ear?

Young coral reef fish with misshapen ear bones are more likely to get lost and die, and exposure to warmer waters makes the problem worse, according to a study of fish living around Lizard Island on the Great Barrier Reef, Australia.

Monica Gagliano at the Australian Institute of Marine Science in Townsville, Queensland, and colleagues found that at hatching, just over half of Ambon damselfish had asymmetrical otoliths, or ear bones.

Gagliano says that as-yet-unpublished work shows that exposing adult reef fish to higher water temperatures and increasingly acid water – both of which are associated with global warming – increases the percentage of offspring born with asymmetrical otoliths.

Increased acidification reduces the availability of calcium to be absorbed by fish to make bones.

“And general stress, such as having to regulate their internal pH when it is changing in the water, also seems to affect the development of otoliths in the baby fish,” says Gagliano.

New Scientist, 6 Mar 2008