I've been making an attempt to inhale everything there is to read about shellfish in the northwestern Gulf of Mexico, and there is not much on the subject without delving into specialized scientific material, which is not as much fun to read as you would think. Little material for the interested layman is what I'm trying to say, and next to nothing about how, when, or possibly where to find live shellfish (oysters aside, of course). All of this has made shellfishing a matter of knowing what could or should be in a certain area, and then finding the critter where the books say it might be, using methods that the books say might or might not work, all the while keeping an eye out for something completely unexpected.
The day after christmas was spent in a good bay. The water had blown out and was staying out. The bay, which is never very deep, was beautifully empty, and there was not enough wind to stir up the few inches of water remaining. Clamming was the game, as the southern quahogs were spitting water everywhere, and it was only a matter of trudging over to a lump and digging the clam up. We were almost at our limits when my clamming partner noticed what appeared to be a long, strange oyster poking just above the surface of the sand, valves open, in three inches of water. I reached down and felt the surface of the shell, and I knew that we'd found a Pen Shell.
The Pen Shell, also called the Sea Wing, Fan Mussel, Jambonneau, Tairagai, and Hoy Jawp, is one of several species of Atrina, and shares characteristics with oysters, scallops, and mussels. They grow to be as long as a foot or more in our waters- none of those pictured above were less than ten inches, and a few were over thirteen. They have the general shape of a mussel, complete with a long byssus, or beard (incidentally, this bysssus was used in the eastern Mediterranean to produce a fabric reportedly finer than silk, called byssa, which was one of the more costly fabrics in history). The shell is black or brown, but if one chips it away, a brilliant metallic inner shell is exposed.
Pen Shells will only be found on sandy or grassy bottoms exposed by very low tides. The good news is that they usually can be found in loose clusters, with two to five animals in a ten square foot radius. As stated before, the Pen Shell lives buried almost up to the tips of its shell. Happily, excavation is quick. Work your hands down the sides of the shell, then slowly pull when you can get a good hold. It would be much easier to use a face mask to find Pen Shells, but I for one have no interest in swimming in the bays during the winter.
Most bi-valves, Pen Shells included, are quite easy to keep alive for several days. Simply fill a cooler with clean seawater that has been strained through a paper towel, and put in the shellfish, starting with clams and heavy creatures on the bottom. Straining the water about once a day is all that is necessary to keep the water barely oxygenated and clean. An added benefit is that shellfish will purge nicely in a day if held this way.
Opening a just-harvested Pen Shell is challenging if one is trying to keep the fragile shells intact. On the other hand, it is easy to remove the meat in one piece if one simply snaps the narrow tip off of the shell. Admittedly, you lose the shell, but otherwise you need to wait for two or three days for the adductor muscle to relax somewhat.
A knife may then be slid between the muscles and the shells. Though you should crack the shell over a bowl to catch any liquid, the majority of the juice that pours out of the shell is water (The Pen Shells valves close imperfectly, allowing in some water all the time). True Pen Shell liquor will be slightly viscous, and the liquor is the last liquid to come out of the shell- don't worry, you will know it when you see it. Upon opening a Pen Shell, one is struck by the very large adductor muscle, which resembles a scallop muscle- though it tastes much better than your average scallop. This muscle is apparently used in Japan for sashimi, and it's the reason I don't care as much for steaming open Pen Shells- you will lose the raw 'scallop'. Don't forget the small disk of meat adjacent to the adductor muscle. When cooked, this little portion looks like jumbo lump crab meat with the the taste of lobster.
Do NOT discard the rest of the organs. They are as edible and tasty as clam and oyster and scallop guts. Due to the size of the Pen Shell, the texture of the guts might not be appealing to all at the table.
However, if minced and used in stuffings, or to thicken sauces or soups, or suitably poached, Pen Shell organs are exquisite. When cleaning the Pen Shells, be sure to carefully inspect all organs, especially the mantle muscle and gonads, for they are known to produce black pearls. We have a small box at home containing 14 pearls we've gathered so far.
Cook Pen Shells in any way suitable for scallops or clams, or let your imagination run wild. Given the number of different textures of meat in the Pen Shell, there is no end to the possibilities. If you are lucky enough to come across them, don't pass up the chance to eat one raw- they have an impeccably clean and sweet flavor. They are certainly one of the best tasting shellfish I have found in our waters.