Swiming Toward Extinction?

A fish coveted by aquarium collectors may be at risk of extinction, scientists warn.

Butterflyfish (C. trifascialis) may start to disappear if pollution and climate change continues to cause coral reefs — their only food source — to degrade, a new study finds.

"We call these kinds of fish obligate specialists. It means they have a very strong dietary preference for one sort of food, and when that is no longer available, they go into decline," said researcher Morgan Pratchett of the ARC Centre of Excellence for Coral Reef Studies Media Release and James Cook University.

To see if the fish would rather starve than eat a mixed diet, researchers exposed the fish to a range of different corals. The fish thrived when its favorite coral was available, but when other sorts of corals were substituted, the fish grew thin, and some died.

The study is detailed in the journal Behavioural Ecology.

The coral which butterflyfish subsist on, A. hyacinthus, are vulnerable to attacks by crown-of-thorns starfish, storms and coral bleaching. Coral bleaching is caused by the heating of the ocean's surface and is thought to be linked to global warming.

Pratchett estimates that up to 70 per cent of the world’s coral reefs are badly degraded and involves the loss of this particular coral.

"The irony," Pratchet says, "is that these butterflyfish are widespread around the world, and you’d have thought their chances of survival were pretty good."

— LiveScience.com Staff

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Credit: Australian Research Council