Age Before Beauty

Among some fish, there's no mom like an old mom

• Laura Tangley
• Jun 01, 2005

Old age has its benefits, especially if you’re a mother fish. Scientists already knew that older, larger fish produce exponentially more larvae than younger ones: 2 million versus 200,000—or ten times more—in the case of Boccacio rockfish. Now Steve Berkeley, a biologist at the University of California–lSanta Cruz, reports that the offspring of big, mature females also grow faster and are more likely to survive.

Berkeley, who studied larvae of Pacific rockfish, was “astounded” by his results. “Survival rates were nearly three times higher, and growth rates were 3.5 times faster for larvae from older mothers,” he says.

The discovery has practical implications. Commercial and recreational fishermen often target larger fish, both because they’re more valuable and because smaller fish are considered the most important for maintaining future stocks. Says Berkeley, “Something is just not right with how we are doing things.”