The Russian military is looking for five dolphins to help out with operations in Crimea. As the AFP news agency reports, the Russian defense ministry announced its search in a procurement document published to its website this week, opening the bidding at 1.75 million ruble ($24,000). The ministry is looking for two female and three male dolphins between the ages of three and five, and it wants them delivered to the Crimean city of Sevastopol by August 1st. The document specifies that the animals should have perfect teeth and "display motor activity," according to Russian news agency TASS, though it does not state the tasks that the dolphins will carry out.

Both Russia and the US have a long history of using dolphins and other mammals to identify submarines, mines, and suspicious underwater objects during the Cold War. Retired colonel Viktor Baranets tells the AFP that Russia's dolphins were even trained to plant explosives on enemy ships.

The dolphins were trained during the Cold War at a facility in Crimea, but the program came to a halt after the fall of the Soviet Union. Ukraine reestablished the training center in 2012, and it is now under Moscow's control after Russia annexed Crimea in 2014. A 2014 report from a state-run Russian news agency said that the dolphin training program was being restarted, but the Russian defense ministry dismissed its claims.

The US Navy has long used dolphins and sea lions to sweep for mines and carry out other underwater missions, though in 2012 it was reported that the animals would be phased out and replaced by robots.