Two men have been jailed for trying to smuggle cocaine with a street value of £1.6m from Colombia to Nottingham in bags of tropical fish.
Olaf Urlik, 33, and Norbert Jarzabek, 32, both from Poland, admitted conspiracy to import Class A drugs at an earlier hearing on 5 January.
The cocaine was dissolved in fluid in plastic bags within larger bags holding the fish, thousands of which died.
Urlik and Jarzabek were both jailed for 11 years at Nottingham Crown Court.
Last April, Urlik and Jarzabek carried out a trial run without the cocaine in which all 16,000 fish were left to die, the Serious Organised Crime Agency (Soca) said.
Jarzabek and a friend from Strelley, Nottingham, collected the consignment and took it to a lock-up garage in Islington, north London, where the fish were abandoned.
A second cargo, plotted by Urlik and Jarzabek and containing 17kg (37lb) of cocaine, arrived at Heathrow Airport on 9 July last year labelled "Live Tropical Fish, Handle With Extreme Care".
It contained 25 double boxes of almost 550 tropical fish.
Soca and UK Border Agency found 10 of the boxes to have dissolved bags of cocaine stored in the water with the fish.
The fish were left for two days at the airport before being picked up.
Once the boxes were collected they were taken to a flat on Glade Avenue, Nottingham, which Jarzabek had rented a month before.
Investigating Soca officers arrested the men at the property with the evidence.
The fish had limited oxygen for at least 96 hours and many were found dead or lay dying. Only 26 survived and were taken to London Zoo for treatment.
The fish are now in an aquarium at the zoo.
Rachel Jones, team leader of the aquarium, said the case was "really quite unusual".
"We do work with the authorities to take confiscations but they're usually of marine creatures like corals."
She said the fish were "very poorly" when they first arrived and were in intensive care for several weeks.
"They were really skinny and they'd been in terrible water quality for many, many days.
"A lot of TLC was involved in encouraging them to feed. Now they're quite plump and doing really, really well," she said.