THE MYSTERY OF THE EEL

Otago Witness, Issue 3803, 1 February 1927, Page 77

THE MYSTERY OF THE EEL

SOME NEW LIGHT. The life story of the eel is sometimes inferred to as “the mystery Of the centuries.” Certain it is that the discussion has been long and frequent, and every little while “discoveries” of one sort find another are made. Last week we received the following letter from Mr Con M‘Kee, Makikihi, bearing on the subject “While reading through an old issue of your paper, February 9, 1926, I read an. article by J. Drummond, F.L.S., F.Z.S., on “The Mystery of the Eel.” I was put fishing for eels in a small stream last night, and caught two eels, one 101 b in weight and the other lib. On opening the large eel I had a look at what we call the float, a long sack filled with air, lying along the backbone. Before evening this, I noticed what looked to be young eels inside. I opened it, and fc■ id them alive (six). I put the sack and its contents into a small bottle, and put some fresh water in it. I was going to put some alcohol in, but thought it might not act, so hope it reaches you in good order. You can forward it to the proper person who can examine same. I have seen several cases like this of other eels I have caught, and after reading" your article, I examined both eels, but found nothing in the float of the small one.” Mr M'Kee's letter and exhibit were submitted to Professor Benham, curator of the University Museum, who kindly replied as follows: — “As I expected from your telephone message this morning, the presumed ‘eels’ are parasites. I have had similar specimens sent to me before on the assumption that the creatures were “young eels.” The object enclosed by your correspondent is the swim bladder, or, as he terms it quite correctly, ‘float,’ in the wall of which as well as the interior, are some of the thread worms, or round worms as they are indifferently called, which are parasitic, nourishing themselves on the blood and other fluids here. The so-called ‘mystery’ of the eel is a journalistic invention, for their life history has been worked out in Europe years ago, and there is no reason to doubt but that the history of the New Zealand eel is similar. At any rate we know as zoological fact that in no fish are the eggs or young contained in the ‘float.’ However, I will not give you a dissertation on Ovigenesis in the animal kingdom, though it is clear that the public are in need of enlightenment.”

Following on this interesting discussion a press despatch from New Bedford in November last may be quoted:— “From the depths of the ocean south of Bermuda have come the first eggs of the American eel known to science. The

discovery was made by a 25-year-old woman scientist, Mrs Marie Poland Fish, biologist of the United States Bureau of Fisheries station at Woods Hole, Mass., it is revealed in the New Bedford Standard. Although modern investigation has solved much of the baffling life story of the eel, all previous efforts to find the egg of either the common American or European eel have been unavailing. The discovery arose directly from the expedition of Dr William Beebe to the Sargasso Sea a year ago, and has been rated as possibly the most scientifically important single outcome of the Arcturus expedition. “The specimens which later were demonstrated to be eel eggs were brought up on the edge of Challenger Bank, ten miles south-west of Bermuda. But only after months devoted to research and verification of her find was Mrs Fish prepared to announce her discovery. “The origin of the eel has been a mystery since ancient times. The inability of the early Greeks to find eels’ eggs or eels ready to spawn led them to attribute their paternity to Jupiter. As has been established since, there was good reason why scientists failed to discover *e*s’ eggs, for the common American and European eels are the only creatures known which live in fresh water, but go to sea to spawn, an exact reversal of the habits of many other marine creatures. “Mrs Fish, larval expert of the expedition, identified the eggs during her work of sorting out a mass of marine specimens brought up in trawling on the vessel’s return voyage. But for a shrimp to which they adhered, they would never have reached the surface in the quarter-inch net. The eggs were a tenth of an inch in width. “The only way to identify a marine egg accurately is to hatch it. One July morning a year ago one egg hatched. A feeble, transparent, ribbon-shaped infant .emerged, which was obviously an eel. Fortunately, in its two days of existence the pre-larva developed to a stage where it could be recognised as a younger brother of the smallest pre-larva previously discovered, a find made by Schmidt, Danish scholar, in 1916. -“Mrs Fish is the wife of Dr Charles J. Fish, Government Biologist. She is a daughter of Mr Addison Poland, Dean of Newark,. N.J., High Schools, and a graduate of Smith College in 1921.