A9Y1BR Great White Shark Carcharodon carcharias Water level view in South Africa (Stephen Frink Collection / Alamy/ALAMY)

Few of nature’s creatures have a reputation for such sharp-toothed ferocity as the Great White Shark, and of the mere half dozen of the fearsome creatures that a Virginia shark survey has captured in 45 years, two were hooked just last week, authorities said.

On Thursday, the Virginia Institute of Marine Science Shark Survey snagged an 8- and- a- half foot immature male, the Institute said.

Then on Friday, the survey’s boat caught another one. This was a mature male, estimated to be from 12 to 13 feet long.

It was hooked in the Atlantic Ocean, about 3.5 miles east of Sandbridge on the coastline of southeastern Virginia.

The first shark was brought on board the survey boat for examination and release. The second, bigger shark, became tangled in a fishing line, could not be brought onto the boat, and eventually got away. “Lost at the boat before we were able” to get it on board, the Institute said.

In online accounts of the shark encounters, the Institute called them rare.

A larger number of sharks of all kinds were hooked, and Institute scientists attributed it at least in part to the relatively cool spring in the region this year. The temperatures affect the available nutrients.

The Institute’s shark survey began in 1973, and the institute calls it one of he world’s longest fishery-independent studies of shark populations.

For all its years-long history, the Institute said, the survey has captured only six great whites. Number five was on Thursday and the sixth was Friday.

A graduate student at the Institute was quoted in a report posted online by the Institute about the hooking of the mature great white.

“When we saw the head,” said the student, Kaitlyn O’Brien, “ it was huge compared to the first one. We were all kind of in shock—it was once in a lifetime..”

In the survey the Institute sends out a boat each summer month on a cruise of five to seven days. Researchers, the Institute said, deploy a long line with 100 hooks at eight places off the coast from just north of the mouth of the Chesapeake Bay to just south of it.

There are many types of sharks. Each one caught is measured, tagged, sampled for DNA, then released, the Institute said. The cruise last week was the first this year.

The mature great white that was lost last week just beyond the boat apparently got something for its trouble.

It chewed into a smaller shark that had also been caught in what might suggest an example of the world of shark- bites-shark.