WAYS OF THE WILD.

Auckland Star, Volume LIX, Issue 171, 21 July 1928, Page 1 (Supplement)

WAYS OF THE WILD.

A NATURALIST'S NOTEBOOK,

N.Z. FRESH WATER EELS.

(Bv A. T. PYCKOVT.)

A correspondent, having road that the European eel migrates to the Atlantic to breed, wishes to know if this is eo and if anything is known of the number of species of New Zealand eels and their breeding places. It has been proved thai, the European eel migrates in the ailtnmn to the Western Atlantic, oft' the southeast of the Bermudas, to breed, and then dies. Impelled by the breeding instinct, the eels make their way down the rivers, and from ponds across the wtt grass to the rivers, and then to the sea. As they near the sea the yellow under-surface assumes a. silvery sheen, while the eyes become greatly enlarged. The sexual organs have not yet shown signs of wakening, nor do they until the migrant* get far out to sea, and thev do 1101 mature until the journey's end. Breed ing takes place in five hundred fathoms, and, spawning having taken place, the participants die. The young eels, orphaned before they are born, one writer has said, slowly make their way upwards towards the light, and, impelled by the Gulf Stream, are carried eastward to the home of their race. Translucent, tiniest, anaemic, thin as a paper knife, with tiny heads, large jaws, and long teeth, they do rot look like the offspring of eels. And hence it was that such specimens as came from time to time into the hands of the man of science were unrecognised. They were simply known as Leptogephali, and labelled as "larvae fish." until in the course of time their identity was established. By the time thev have attained to a length of about a*id a-half inches they have reached ;1h ; - maximum size as larvae. Tl\er becins a strange transformation. Thehrsrin to grow smaller, and this be—;nise -he head is closed during alteration- deeding impossible, the body is i ' 'need to sustaining itself by absorbing us o »n tissues. Little by little it shrinks unti. from the shape of a willow leaf it becomes cylindrical, fins develop, and the blood acquires its crimson hue. It is now what is called a glass elver. Presently a little pigment tinges the still transparent body, and at this stasre the. up-river journey begins. As elvers the fish swim up the rivers in great numbers. No obstacle suffices to bar their progress. They will squirm up mosscovered rocks and make their way overland through the wet grass to ponds and pools far from the river. Two Species of New Zealand Eels. Professor Johe. Schmidt, Director of the Carlsberg Laboratory, Copenhagen, spent many years investigating the classification and migrations of tinAtlantic species of eel. It is due principally to his investigations that the life history of the European eel is known. Dr. Schmidt recently turned his attention to the eels of the lndo-Pacific region. In 1926 he visited the Southern Pacific, Australia, New Zealand and Tahiti, and obtained on the way great quantities 01" eels—sufficient for a statistical investigation. Dr. Schmidt states the fresh ' water eels are probably more abundant . in New Zealand than anywhere else in c the Southern Hemisphere. For the Maori y they were of the utmost economical j importance, as is evident, for instance, , from the highly developed technique in methods and implements for the capture * of these fish possessed by the native* prior to the arrival of the Europeans. By means of statistical and other inves- ! tigations of nearly fifteen hundred eel* ' from New Zealand Dr. Sc-limidt has now definitely ascertained that there are two - valid species of the genus Anguilla (from . the Latin anguilla, an eel), both highly ' variable, though hardly more so than the European eel. They should be called the sliort-finned eel. A. Australis and the long-finned eel. A. Aucklandi. Both species are uniformly coloured. The most conspicuous difference is the length of the dorsal fin, which in A. Aucklandi extends a considerable distance in front of the vent. The distribution of the species is as follows: A. Aucklandi belongs mainly to the south and west, and A. Australis chiefly to tbe north and east. It is the common eel about Auckland. In England large quantities of live eels are imported from Holland. Tbe dwellers in the crowded cities in England are the principal purchasers of eel pies and stews, which are delicacies. Probably owing to fresh water eels not being placed on the market in Auckland their food value is unknown. In Denmark the. eel fisheries produce an annual revenue of £100,000. Breeding Places of New Zealand Eels Unknown. Mr. Gilbert Ar ley, curator of the Auckland Museum, contributed a paper on fresh water eels and their life history, in 1924 to the "N.Z. Journal «.f Science and Technology," and states the question "Where do eels breed V" has long waited for an answer, and the story of the wonderful breeding migration of four thousand miles of tbe European eel sucguests this question. Mr. Archev states A. Aucklandi, which may be called the New Zealand fresh water eels, is confined, so far as he could discover, t<» New Zealand and the Auckland Island?, whereas A. Australis has been taken from Timor, Eastern Australia. South Australia, Tasmania. New Zealand, and the Auckland and Chatham Islands. As to their probable life-historv wo do know that Leptoeephali are occasionally taken off our coasts, but wo do not know of which eel they are fho larvae. Hie absence of eels from above larL'e waterfalls also points to a marine spawning migration. The actual spawning place, however, can only be gue.-srd. , we _ acc ept the present specie.- and their distribution as correct, arid if \* ifurther suppose that the breednii; p'.i<» (of A. Australis. at any r.ue- j- <ome central spot in the tropical par: of the Pacific, we have to & spot from which currents flow to all j.laecs in which A. Australis lives. The maps I have consulted d>> tot show such a spot, unless it b« the east. Central Pacific, vvhen-e curr-nts go to all tho.-e places except S Australia and Tasmania

Frost Fish. Mr. A Nifjmlriiii. a former ;i t flip K ; . r of I s binds. referring t•> a rcifnl article on fro-' li.-li. ilio r.. 1 - lowing particulars of the finding <>ft:• o~■ fish at the Bay of Islands.—'".Mv w:fe remind* nie thirt tho largo?: n;t vo! trost lisJi stranded in °ne -e,i--m <.n tile i„.aoh of the little lay ii= "hieli we Ji\ (•<-?. known a? Second M.-it.iwhi. was eighteen. One •'H'T'i""!. iiio came in .•i.MUit -"i />■'»•• lime others jinnic ashore <r. lilu early TnornitiL'. (Although tint 'i -' i i- evidently a l ] c pp.<,'n /Mi. ?•• ! tiivy conic tu'the I -hallo» >v;it.-r- >:•(' T ]),. I ,ay to spawn. On ,ne a-).. If, „„a a Aoniijj frost, ti*h. about imlios Jong, at the head of the tide at Waikare.