The producer's French version of the ingredient list, stamped on the can, is the following: "Ingredients: 180 crevettes et plus, eau, sel, sucre, exhausteurs de gout: E621 (glutamate monosodique), acidifiant: E330, antioxygennes: E223, E685".
I don't know if the importer is concsiously hiding the fact that the product contains harmful monosodium glutamate (E621), which causes light forms of addiction, distorts the sense of taste, may cause obesity and is thus not recommended for children. Most people usually don't know what side-effects E621 produces. However, a few months ago there was an article about it on Delfi, the most popular news portal, so quite some people must have read it.
I can never memorise the codes for all of the harmful chemicals, but I try to avoid those that I know. It is very difficult, if not impossible, to avoid E621 if you like herring or chilli nuts.