Here one can buy groupers, snappers, leather jackets (沙鯭), octopus, cuttlefish, giant prawns, shrimps, mantis shrimps, fresh water crabs, sea water crabs, rays, clams, snails, lobsters, … There are many species that you won’t find even in a respectable aquarium.
And you buy them by the bucket. A bucket of 10 small leather jackets costs less than 100 HK dollars. But a bucket of a big grouper can cost hundreds.
A fair amount of trust is required for the buying and selling to occur. After the product, the processing (skin those leather jackets) and the price are settled, the vendor in the most delivers the product in a net at the end of a long pole, to the customer more than 10 feet up on the seawall. The customer retrieves the product, and then places the money in the net. The vendor collects the money and then delivers the change, if any. Both sides have to trust that the other side would honour the agreement, which is purely verbal and often not very explicit - what if the customer collects the fish and then walks away?
Trust between strangers is more important than we often realize.