Local media say that the beautiful octopus, which features in the James Bond film Octopussy, has become one of the most popular purchases at Bangkok's main pet market.
It seems that buyers were not deterred by the warning that there is no antidote for their new pet's lethal venom.
It is just the latest exotic pet to captivate the country. A ban was imposed last week on keeping the Madagascan hissing cockroach, which can grow up to 10 centimetres (4 inches) long and live for seven years.
Jail threat
The Thai fisheries department told the French news agency AFP that it had issued a plea for new owners of the blue-ring octopus to co-operate with the authorities:
"We have put out an announcement asking all owners to surrender them to us, particular those who are no longer able to look after them," an official from the department said.
Traders are selling the animal, whose rings glow electric blue when it is threatened, for 800-1,000 baht ($19-24).
The official warned that those found importing the animal, which is believed to have been brought in from the Philippines, could face a 10,000 baht fine, or six months in jail.
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