The French love seafood, and that's clearly reflected in their supermarkets. The seafood section is just as large as the meat section or fruit section, and it's a sight for the eyes indeed. The employees do take their time to arrange the seafood in a manner that's appealing for the eyes, sometimes it's all artistic and very creative, such a shark with a fish in its mouth.
These pictures are from Carrefour in Bay2 in Torcy outside of Paris. This Carrefour has a very varied selection of many products, including international ones. You can even find Marmite and parsnips here.
There are several people attending the fish section, and you can get your fish prepared just as you want it. Prices are per kilo usually.
Yes, it is a stingray that's been partially prepared. I've seen sharks lined up as well, huge tunas and salmon and anything you can imagine.
Oysters are very popular in France and you can find them for any celebration. The shrimps are usually hot water shrimps from the Mediterranean or the Indian Ocean, though with luck you can find some from the North-east Atlantic.
The crabs are alive, pretty spooky as they lie there watching you. There are more shellfish available than I even know the names of. You can also find the French lobsters in a tank where they stare at you.