Why do leopard sharks flash their white bellies in Southern California? Student researchers are on the case

SAN DIEGO — It's no secret to most San Diegans that leopard sharks come each summer to warm their pregnant bellies on the sand at La Jolla Shores. But much still remains unknown about these animals. Andrew Nosal, an associate professor of biology at Point Loma Nazarene University, has spent the past several years trying to unlock their secrets each season while they are here. Such as why so many gather here in the first place. And why they flip on their backs to rub against the sand, an action first noticed last summer. Nosal has always mentored undergraduates who have helped with field work. ...