TOKYO - Octopus and whelks caught off the coast of Fukushima went on sale Monday at supermarkets and retail stores in northeastern Japan's Soma City, marking the first sale since the Fukushima nuclear plant crisis.

Local media cited a local fisheries cooperative saying that no radioactive substances were detected in the seafood caught during Friday's trial fishing in waters more than 150 meters deep and 50 kilometers off the coast of Soma. The products were boiled before being shipped to the local retailers.

Some of the seafood were sold about 40 percent cheaper than usual market prices, media said.  

The Fukushima Prefectural Federation of Fisheries Cooperative Associations said the trial sale is aimed at gauging demand and market values of the particular species chosen for low levels or none of radioactive contamination during monitoring of 163 marine species from April last year.

The association plans to expand sales of Fukushima seafood after another trial fishing session scheduled on Wednesday, according to media reports.