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.