July 6, 2015 — Rutgers marine researchers and New Jersey fishermen are piecing together the details of the strange, gender-bending sex lives of black sea bass – a study that could improve understanding of the bass population and help the beleaguered recreational fishing industry.

Scientists have long known black sea bass are “protogynous hermaphrodites,” a species in which fish that begin life as females can switch gender to male. But the details of how and why that happens are not completely understood.

Now, there’s thinking the change is triggered when the number of males in a local population declines.  Not enough guys? Some black sea bass ladies make the switch.

“It sounds crazy, right? But from an evolutionary perspective, it’s a perfect way to keep balance in a population,” said Olaf Jensen, an assistant professor with Rutgers’ Department of Marine and Coastal Science leading the project. “If it’s operating out in nature, maybe we don’t have to worry so much about fishing pressure removing the big males and skewing the sex ratio.”

This self-propelling sex change could help biologists and government fisheries managers to better assess the overall black sea bass stock, calculations that up to now have been forcing season closures and lost money for the shore’s party and charter boat fleet. Ignoring the influence of sex changes on population dynamics could lead to mistakes in estimating the stock size and how fishing seasons and catch limits should be set.

Read the full story from Rutgers University