Known by the scientific name Telmatoius culeus and as the Titicaca water frog, it also has the nickname of "scrotum frog."
Eight inmates in total have died with symptoms of COVID-19, according to Cox, spiking concerns that the virus will spread throughout the prison population.
Bolivia is due to hold general elections on Sept. 6. The elections were originally planned for May but delayed due to the pandemic.
Mexico complained of "excessive" surveillance by about 150 Bolivian intelligence and security service personnel on Monday.
Her government has also set up police units to conduct counter-terrorism operations. TV footage broadcast on local media have showed police in face masks with guns in training sessions.
The military had asked Morales to step down after weeks of protests.
The attorney general's office announced that it had ordered an investigation with the aim of prosecuting the members of the electoral body and others responsible for the irregularities.
Morales, 59, South America's longest-serving leftist leader, won 45% of votes, compared with 38% for the more conservative Mesa.