Shells are where you find them

摘要

Many people have heard of the lobster walk, where one night of the year lobsters migrate in mass (Fig. 1). I have not seen lobsters migrating, but I have seen a Strombus alatus (fighting conch) migration. In January 1971, I took a visiting Canadian commercial diver friend for a dive off Ft. Lauderdale, Florida. I enjoy potluck, or dumb luck, diving-just trying an unknown spot. We threw the anchor over in 40' of water on a sand bottom and, reaching the bottom, saw hundreds, if not thousands, of fighting conchs (Fig. 2). They were all moving north, just inches or feet apart. I sent the other diver up to the boat for a larger bag and gathered up a few shells for the bag. We left the others. After getting back on the boat, I took several shoreline landmarks to find the spot again, and returned two weeks later. All of the live shells were gone, with one dead one remaining. I can only guess the reasons for the migration. The shells were moving north and slightly towards the shore. The nearest inlet was Hillsboro Inlet. I had snorkeled there a few years earlier and found several small, juvenile live shells. Perhaps the strombs were going there to spawn.