A new species of clione sea slug has been found in Toyama Bay, a local university said Thursday.

The discovery was made by a team of researchers led by Zhang Jing, a professor at the University of Toyama's graduate school. Zhang has been studying the ecological system in Toyama Bay, one of the deepest in Japan.

Researchers have confirmed that the species — the fifth of its kind — has not previously been seen.

"It's surprising to find a creature of the cold ocean (near the Arctic) in a place so far south," Zhang said.

Zhang's team collected about 30 cliones last August and roughly 100 earlier this month in the bay's waters at a depth of around 1,000 meters.

"The new species' habitat situation could be an important benchmark in researching rising sea temperatures," said Zhang, who added that she plans to release a scientific name after publishing a thesis.

Last year, a new clione species was discovered in the Sea of Okhotsk, the first such discovery in about 100 years.

Cliones, which are also known as sea angels, mainly inhabit cold waters in the polar regions. The university said the new species, measuring about 5 millimeters, could be native to Toyama Bay at a depth of 300 meters or greater, where the water temperature is low.