An Osaka Prefecture university known for a technique to cultivate bluefin tuna has succeeded in incubating and growing Japanese eels, an endangered species that is a sought-after delicacy.

Kindai University, which sells the tuna it farms, said Friday it grew the eels for 50 days and aims to achieve "full-cycle" aquaculture of eels — breeding the eels it incubates and cultivates — for commercial use.

In 2002, Kindai University became the first institution in the world to achieve full-cycle aquaculture of bluefin tuna. The fish has gained popularity as "Kindai tuna."

"With eels as well, we will try to achieve sustainable aquaculture without depleting natural resources," said Shukei Masuma, head of the Aquaculture Research Institute of the university, based in Higashiosaka, Osaka Prefecture.

Efforts to cultivate Japanese eels, designated as endangered by the International Union for Conservation of Nature in 2014, have been led by the Japan Fisheries Research and Education Agency, which achieved a world first when it succeeded with the full-cycle farming of eels in 2010.

The domestic catch of juvenile eels for cultivation fell this season to 3.7 tons, the lowest level since 2003, when comparable numbers became available, government data showed.

Kindai University said about 30 eel larvae, which were artificially incubated on Sept. 12 at its research facility in Wakayama Prefecture, grew to about 2 centimeters over 50 days.

The university is separately growing around 1,100 larvae. If things go smoothly, some of these are expected to grow to a marketable size by next spring.

In a bid to cut back on aquaculture costs and workloads, Kindai will try to develop a feed that is less likely to pollute water, according to the university.