Previously scientists had suspected that sawfish—large ocean and freshwater fish found throughout the tropics—use their saws to probe sand or mud for prey.

Now, preliminary experiments suggest that the fish's long, tooth-lined saw are full of pores that can detect movements or electric fields of passing prey—acting as a sort of "distant touch," Barbara Wueringer, a sensory neurobiologist at the University of Queensland in Australia, said by email.

This skill is especially handy for nosing out dinner in murky or dark waters, Wueringer said.

The saw—a cartilaginous extension of the skull—also doubles as a weapon, the new research suggests. Lateral swipes can split smaller fish in half, she observed during experiments in the lab.

"We know so little about sawfish, even though