The discovery of a new species of clione sea slug, usually found in chilly polar waters, in central Japan's Toyama Bay may shed light on sea temperature changes, 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. Researchers in Japan have confirmed through gene analysis that the species -- the fifth of its kind -- has previously not been identified.

(Shellfish Museum of Rankoshi/University of Toyama)

"It's surprising to find a creature of the cold ocean (near the Arctic) in a place so far south," said Zhang, who has been studying the ecological system in Toyama Bay, one of the deepest in Japan.

Zhang's team collected some 30 cliones, also known as sea angels, in August last year and roughly 100 earlier this month in the bay's waters at a depth of around 1,000 meters.

"The new species' habitat situation can be an important benchmark in researching rising sea temperatures," the professor said.

Zhang said she plans to release its academic 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.

The university said the fifth species, measuring about 5 millimeters, could be endemic to Toyama Bay at a depth of 300 meters or more where water temperature is low.

(Shellfish Museum of Rankoshi/University of Toyama)