When I buy fish, I always try to select ones that look “fresh.” But I often find it difficult to determine whether a fish is fresh. According to The Healthy Fish, when buying fish at the grocery store:
Check the Texture. The meat of the fish should be firm, moist and freshly cut without any dry spots. …
Beware of Strong Fishy Smells. …
The Eyes are the Window to the Freshest Fish. .
That advice is similar to advice from a hundred years ago. Here’s what it said in a 1920 home economics textbook:
Fish has always been used in place of meat (Fig. 209). In general it has much the same composition and food value as meat and is as easily digested. In most localities it is cheaper than meat. Fish is always at its best when used just after it is caught (Fig. 210). However, great quantities are frozen and are kept for long periods of time.
Fish spoils very easily and needs to be cooked or put into storage at once. If you live near the sea coast or near lakes or rivers where fish is caught, you should have no difficulty in getting fresh fish, but if you do not, you should be careful when buying to select fish with firm flesh, pinkish gills, and bright eyes; it should not have an offensive odor. If the fish is frozen, it should be cooked immediately on thawing it out. Unless good fresh fish can be bought it is more satisfactory to use salt fish or the canned product.
Arts for Home and School, Vol. II (1920) by Anna Cooley and Wilhelmina Spohr