Customs officers at Manchester Airport have seized the largest illegal shipment of live coral detected coming into the UK.
The coral was transported from Indonesia via Malaysia
The banned or unlicensed corals, worth £50,000, were spotted in air freight from Indonesia.
A spokesman said the smuggled creatures were destined for specialist shops across the UK.
Traders in Manchester, Cheshire, West Midlands, Yorkshire and Scotland have since been warned about illegal sales.
The coral has been transported to London Zoo, where tanks large enough to cope with them are available.
Brian Zimmerman, head keeper of the zoo's aquarium, said the majority of the corals survived the trip from the Asia.
He said: "It is disheartening to see so many protected species being smuggled into the UK.
"These species are vulnerable to over-collecting which is why their trade has been banned in the EU."
HM Revenue and Customs officers seized the freight shipment of 350 live corals and clams, including a significant number of rare species, in September.
The discovery was kept confidential until checks on the various aquarium businesses involved had been made.
An investigation into the smuggling operation is ongoing.