(CNN) Russia's military is looking for new recruits.
A document on an official government website detailing state purchases stated that the Ministry of Defense of the Russian Federation is looking for five bottlenose dolphins, three male and two female, required for military duty. Other specifics include the length of the animals (2.3 to 2.7 meters) and their ages (between 3 and 5 years old).
The military is looking to pay 350,000 rubles (about $5,000) each for the dolphins. Careful not to get duds, the report stipulates that the animals "should display motor activity."
The document also says there should be no visual damage on their skin. They should have all teeth without scratches or cracks, minimal breathing rhythm should be two breaths per minute, maximum -- four.
Among the requirements, it also says "bottlenose dolphins need to demonstrate physical activity."
The purchase order stipulates that the dolphins be caught in the presence of marine mammal specialists and transported humanely, in bathtubs filled with seawater, the report states, according to Russian state media.
Animals have long played roles in war, from Alexander the Great's war elephants to cavalry used as late as the second World War. Dogs have been used for a wide range of tasks, from delivering messages and laying communication lines to sniffing out mines.
Dolphins themselves have been aquatic service animals in the past -- both for the U.S. Navy, which also trains sea lions for military purposes, and for the Russian military -- as these highly-trainable mammals are able to detect risks such as sea mines or enemy scuba divers trying to slip through blockades or into restricted areas.
While the new dolphin brigade's purpose is not evident from the purchase order, Ukrainian war-dolphins found themselves forced to change allegiance following the Russian annexation of Crimea in 2014.
"The combat dolphin program in the Crimean city of Sevastopol will be preserved and redirected toward the interests of the Russian navy," state-run Russian news agency RIA Novosti reported at the time.