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According to online reviews and directories, the market that sells dried seafood on Shi tang Lu (石塘路) in Shanghai is likely referring to the Dried Seafood Market (干海鲜市场).
As for its operating hours, according to Google Maps, this market usually operates from 7:30 AM to 6 PM. However, please note that these timings might be subject to change or varying depending on factors such as seasons, holidays, and government regulations.
If you are planning a visit, I recommend calling the store directly for up-to-date information or checking their social media platforms before heading there.