Japanese government officials say China has not applied for permission to keep importing nishikigoi carp, and as a result, shipments of the ornamental fish to China have been suspended.
Japanese Fisheries Minister Miyashita Ichiro said on Friday that the government submitted the documents to the Chinese side, which is yet to report back that it has completed the process. He added that "the deadline expired at the end of last month."
China is the biggest importer of the Japanese carp. Last year it bought an amount worth 1. 2 billion yen, or nearly 8 million dollars.
The fish are required to undergo quarantine at Japanese facilities that are approved by China.
Beijing has suspended all seafood imports from Japan over the release of treated and diluted water from the Fukushima Daiichi nuclear power plant.
Miyashita said nishikigoi are farmed, which means they are very different to fish from the ocean. He said he can't see any link to the seafood ban.
The minister said China has been applying measures that are not based on scientific evidence. He said Japan will keep lobbying Beijing to abandon irrational measures that hurt trade ties.