The custom of eating fish for Christmas is more a practice in certain ethnic communities rather than a mandate by the Catholic Church. The roots for the particular instance you mention lie in southern Italy-some say Sicily, others say Naples, and yet others say it goes from Rome on down, especially in the coastal towns.
Early Christians used to fast all day Christmas Eve, not eating until after they received communion at Christmas Mass. This practice evolved into a vigilia di magro, a day of fasting, and abstinence like those of Lent, when the faithful are asked to forgo meat as a penitential gesture. Eating that seven-fish feast, the cena della vigilia (“vigil meal”), was to break that fast at the end of the day, before heading to midnight Mass. Meat proper was not consumed or even prepared until after midnight for dinner Christmas day.
No one seems to agree on what the seven fish symbolize: it may be the days of the week, or the “days” it took for God to create the cosmos, among other things. There is also no consensus on which seven kinds of fish to include on the menu, let alone whether it is more important to have seven different varieties or just seven separate dishes. A typical lineup, though, might include:
– baccala (dried cod)
– calamari (squid)
– whitefish or flounder
– mussels or oysters
And this doesn’t even include the antipasto or the dessert yet.
Yet other Italian traditions would have you serve three fish dishes (= three Wise Men, or Trinity), nine (3 sets of three – my guess: 3 wise men, trinity, Holy Family), twelve (= apostles), or thirteen (= twelve apostles + Jesus). In any case, the fish is the point. And these days, the notion of fish is taken to mean seafood, in general, so don’t be surprised if calamari, shrimp, or lobster bits turn up on your plate.
Other local cultures and ethnic groups-some Czechs, Poles, and Portuguese, for instance-also report Christmas fish traditions of their own. A traditional Polish Christmas Eve dinner boasts twelve dishes, one for each month of the year, and this feast generally starts with some kind of fish in horseradish sauce. The practice has as much to do with proximity to good fishin’ as with faith and tradition proper. If you hear about or know of other folks with similar customs, by all means let us know.
Rachel Bundang, Theologian