Science: Eel Eggs

Last week the New Bedford (Mass.) Standard had the honor of publishing a scientific story of considerable interest and special appropriateness for that oldtime fishing centre. Mrs. Marie Poland Fish, biologist of the U. S. Bureau of Fisheries station at Woods Hole, Mass., in working over specimens and data brought back by her husband, Dr. Charles J. Fish, from his trip last year to the Sargasso Sea, Galapagos and the prehistoric gorge of the Hudson River, had identified certain fish eggs dredged from the Challenger Bank near Bermuda as eggs of the common American eel. Science had never seen such things before. The identification was by a sure method: the eggs hatched.

Eels, the only freshwater dwellers that descend to salt water to breed, are caught in great numbers and sizes (up to 8 ft., 3 in. for congers) as they go to sea in the autumn but the specimens are never sexually ripe. Sea dredging has hitherto brought to light no eel eggs, which are evidently laid at great depths. Laboratory observations have proved that eels spawn but once, dying immediately afterwards. All that ever comes back from the depths are transparent baby eels about 2 in. long, with which harbors and rivers teem in the spring. Before spawning, matured eels fast for months, their ultimate death resulting from starvation. The small eels that return by the myriad are at least a year old, having developed out of a larval stage which Science long took to be a distinct species of surface-dwelling fish, leptocephali, notable for their complete lack of reproductive organs. The presence of eels in waters blocked from the sea by high falls, and in land-locked ponds and lakes, is readily accounted for by the eel’s ability to live a long time out of water, to travel considerable distances overland at night, through wet grass or during damp weather. The ancient Greeks, perplexed by eels’ habits, considered them Jupiter’s spawn.