Researchers at the University of Aberdeen in Scotland recently broke their own record for deepest recorded fish twice in one expedition.

While exploring the Mariana Trench -- the deepest place on Earth at nearly seven miles beneath the ocean surface -- scientists observed two new species of snailfish. The first, seen between the depths of 6,000 and 8,000 meters, momentarily broke their previous depth record of 500 meters.

The second snailfish, and now the world record holder for deepest fish, was filmed at a depth of 8,145 meters -- a little more than five miles beneath the ocean surface.

"This really deep fish did not look like anything we had seen before, nor does it look like anything we know of," Alan Jamieson, a deep sea biologist at Aberdeen, said in press release. "It is unbelievably fragile, with large wing-like fins and a head resembling a cartoon dog."

Jamieson and his colleagues also happened upon a type of massive amphipod known as a supergiant. The enormous crustacean was first discovered in 2012, when it was snared in traps off New Zealand coast.

The many discoveries were part of the 30-day Hadal Ecosystem Studies (HADES) expedition, carried out by a fleet of submersibles controlled from the ocean surface. Scientists credit their unique finds with the decision to take their time during the descent, sampling a range of deep ocean environments.

"Many studies have rushed to the bottom of the trench but from an ecological view that is very limiting," explained Jeff Drazen, a biologist at the University of Hawaii and co-chief scientist on the expedition. "It's like trying to understand a mountain ecosystem by only looking at its summit."