Tomorrow, many Christmas Eve dinners will be eaten, and the most Zantac will probably be required at any home or restaurant featuring the Italian meal, The Feast of the Seven Fishes. While it usually has seven dishes, some actually make more. Mario Batali told Epicurious, "No one's quite sure of the significance of the number. Some families do seven for the sacraments. Some do ten for the stations of the cross. And some even do 13 for the 12 apostles plus Jesus."

The meal's origins are rooted in the Italian tradition of fasting before Christmas. Which means no meat—so fish is on the plate. Louis Balducci, who owns fishermonger Agata & Valentina on the Upper East Side, told Edible Manhattan last year, “Oooooo, yeah, it’s a crazy time in the store for fish! Overnight, we have guys cleaning shrimp and squid. We have live eel, merluzzo, fresh scungilli, live snails, fresh anchovies and sardines. We’ll bring in more baccalà [dried salt cod], of course, because it’s so popular that time of year. We have razor clams, sea urchin, head-on shrimp. And we sell more whole fish at that time, like orata and branzino. I work on Christmas Eve, always. For the last 25 or 30 years. But I love it! It’s a madhouse, but it’s fun. I love to watch people shopping for that dinner. It’s one of my favorite days of the year."

Batali offered Epicurious a Feast of the Seven Fishes menu, including salt cod, baked eel and spaghetti with mussels. Patsy's Restaurant on West 56th Street shared a Lobster Fra Diavolo recipe with WCBS 2. And Hearth Restaurant on East 12th Street, which has a Feast of Seven Dishes menu tomorrow night, suggests maybe the seven number is associated with Mickey Mantle.

In today's NY Times, Paul Greenberg and Carl Safina give their picks for an ecologically-conscious Feast of the Seven Fishes menu, selecting seafood from around the country and world.

We start close to home: blue mussels, farmed in the coastal waters of New England and Atlantic Canada. Delicious when prepared as Cozze alla Triestina and as rich in omega-3s as salmon, mussels filter algae and particulate matter, improving water clarity, limiting nitrogen loading and thereby slowing the spread of oxygen-deprived dead zones. Humans have depleted wild bivalves, and in their places dumped untold tons of sewage. Part of reversing this pattern is to farm mussels, and to encourage mussel farming, we should encourage mussel eating. So, with mussels, knock yourselves out.