As mentioned below, there was no signage, so I can't provide a complete species list, but the species I saw were: Common sole, plaice, flounder, sea stickleback, three-spined stickleback, shore crab, and common whelk.
Limfjordsmuseet is a small maritime museum and aquarium in the Danish fishing village Løgstør. The exhibition mostly details the fishery and history of the Limfjord area in Denmark. The aquarium only consists of around 15 species in eight tanks and one touch pool, making it the smallest public aquarium in Denmark. Unfortunately, there's no tank signage at all, also making it the least educational aquarium in Denmark.