FISHERIES RESEARCH BOARD OF CANADA Translation Series N 2505 The European eel by V. Kokhnenko Original title: EvrOpeiskii ugor' From: The European eel, : 1-108 1969 Translated by the Translation Bureau(PHY) Foreign Languages Division Department of the Secretary of State of Canada • Department of the Environment Fisheries Research Board of Canada Biological Station • - St. Andrews, N. B. 1973 • 162 pages typescript j,,._^^. P[^IR6 1.565 DEPARTMENT OW '' .-• ŸÂRY"OF STATE SECRÉTARIAT D'ÉTAT TRANSLATION BUREAU BUREAU DES TRADUCTIONS MULTILINGUAL SERVICES DIVISION DES SERVI&CES CAPIADA DIVISION MUMULTILINGUES I rRA4SLhTED FROM - TRADUCTION OE INTO - EN 511 ssian i;naY^.ish ^UTNOR -- AUTEUR _^- ^,^,------- --- T1o lï.hlle2î.l;0 ., V TITL' INENr,LISH - TITRE ANGLAIS The Llttropean- eel TI.TLE IN FOREIGN LANGU.fGE (TRANSLITERATE FOREIGN CHARACTERS) TITRE EN LANGUE ETRANGERE ( TRANSCRIRE EN CAP.ACTÉRES ROMAINS) Evropeisk7 ï ugor' P.EFERENCE IN FOREIGN LANGUAGE (NAME OF BOOK OR PUBLICATION) IN FULL. TRANSLITERATE FOREIGN CHARACTERS, REFERENCE EN LANGUE ETRANGERE (NOM DU LIVRE OU PUBLICATION), AU COMPLET, TRANSCRIRE EN CARACTÉRES ROMAINS. As above le ERENCE IN ENGLISH - REFERENCE EN ANGLAIS k :S above PUBLISHER - EOITEUR PAGE NUMBERS IN ORIGINAL DATE OF PUBLICATION NUMEROS DES PAGL'S DANS Fishchevaya Frorr>wrsh7.enn.ost t DATE DE PUBLICATION L'ORIGINAL (1•ïn.ist*ry of the Food Industry) 1-108. YEAR ISSUE NO. VOLUME ' PLACE OF PUBLICATION ANNÉE NUMERO NUMBER OF TYPED PAGES LIEU DE PUBLICATION NOMBRE DE PAGES DACTYLOGRAPHIEES r-OSCOu., UâSR ].;6g I62 REQUESTING DEPARTMENT TRANSLATION BUREAU NO. MINISTÈRE-CLIENT Environment NOTRE DOSSIER NO JA 3.6f)-6 BRANCH OR DIVISION TRANSLATOR (INITIALS) k,lshexies Service DIRECTION OU DIVISION- TRADUCTEUR (INITIALES) P. Ily. Fisheries Research Board of Canada PERSON REQUESTING DEMANDÉ. PAR V2k7ENLri:D Ti'LA1'1SLATVO1Y) For only YOUR NUMBER 76y-18-1li VOTRE DOSSIER NO ?"RADtSC1'1'^,-,N fiiOt1 RE^-^6 âE,"C Ît1iUriTîi3l'n+iSn seLijt„ti'3Q`3^o DATE OF REQUEST DATE DE LA DEMANDE November 22, 1972 501,2OC.110•15 (RF_V. 2/68) 7tJ0-7.)-029•53;)3 DEPARTMENT OF THE SE-CRETARY OF STATE SECRÉTARIAT D'ÉTAT . TRANSLATION BUREAU BUREAU DES TRADUCTIONS MULTILINGUAL SERVICES DIVISION DES SERVICES DIVISION MULTILINGUES ---W-Ufï-No. DEPARTMENT DI VISION/BRANCH CITY NO DU CLIENT MINISTE' RE DIVISION/DIRECTION VILLE Environment Fisheries Service Fisheries Research Board o -.& St. Andrews, N.] t.nnaan - — SUREAU NO. LANGUAGE TRANSLATOR (INI TIALS) N 0 DU BUREAU LANGUE TRADUCTEUR ( INI TI ALES) 143666 Russian P. Hy. APR 1 21g73 UN El'Y.T.Z1.) TilA'„,!\1:17)N For in 1-n c.-.I/ TRt.,,.E.)UCTUZ,N NON REV1SEE Izdaterstvo "Pishchevaya promyshlennost" Inform-Ai-ion (Food Industry Press) - Moscow - 1969 • THE EUROPEAN EEL UDC 597.555.2+669.213 S. V. Kokhnenko Edited by Dr. Biol. Sc!. P. A. Dryagin 5Os-'2 00-10-..31 7 530•2111-5532 TABLE OF CCUrEU23 • • 2 Preface 3 The Biology and Distribution of the European Eel 5 Systematic position and distribution 5 Eorphological characteristics 13 Life cycle ,0 Différentiation of sex and sex differences 40 Age and its determinatibn 51 Habitat and food supply 57 Dimensions and growth of eels 67 The condition factor 74 The nutritive qualities of eel meat . 76 Specific properties of the blood 80 Diseases of eels 83 Eel Breeding in Inland daters 96 Stocking material and sources of its supply 96 Stocking lakes with young eels Commercial. return and prediction of the eel catch 111 ilethods of catching eels 117 The catch of eels in the epublics of the USSR 130 The profitability of eel fishing and the outlook for its development in the USSR 137 Note on the Bibliography 141 Bibliography A: Translation pf references in Russian 142 B: References in languages other than Russian 152 2 • ^_LP, "Jf)Cr: f}'çTï_i,•o, {;'- nE:Ot2'PT'I^_ZCF.! 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"'-;^'•- ^P': ^SE?.' ^Ir^ .-. ?7c^.',- :C7 PREFACE One of the main problems in the science of fisheries is the development of a•sound biclogical basis for improving the icthyofauna -end . increasing the fish productivity of inland waters. An important contribution to the accom- plishment of this task is made by the introduction of valuable fish species. The European eel -- Anguilla anguilla L. -- is very promising from this point of view. It is an excellent food with a pleasant taste, it is tolerant of wide changes in its external environmental conditions, and it can forage in all manner of different lakes, reservoirs, rivers, ponds, and inlets of the sea. The biology of the eel during the period of its freshwater life has been inadequately studied despite an extensive literature (Walter, 1910; Schmidt, 1932; Frost, 1945; Bertin, 1956). Although eel breeding is a very promising branch of the fishing industry, before it can be developed certain items of information are absolutely essen- tial; the biological characteristics of the eel.durings its life in lakes, its growth and development, its sex ratio, its ecological parameters, its range of utilizable foodbateriels, its feeding habits in relation to other species of fish, biological breeding techniques, and other problems. .0ver a . period of 14 years (1952-1966) the author has studied the biology of the European eel reared chiefly in White Russian waters _'the - Braslav, Narocht, Uklyanskaya, Polotsk and Vitebsk groups of lakes, and in the rivers Neman (Niemen), 'Zapadnaya Dvina (Western Dvina), Dnepr (Dnieper) and Pripyatl (Pripet)j, and to a lesser extent in .the Baltic States. In 1960 the opportun- ity was taken of studying eel breeding in the Adriatic. In this book, drawn frcm my own experience and frcm data in the litera- ture, I have attempted to give a more complete picture of the biology of the eel and to present the basic facts regarding the development of eel rearing 4 in the Soviet Union. I wish to record my gratitude to Dr. Biol. Se. Professor P. A. Dryagin for his valuable advice wbilf'. the book was written, to Corresponding Member of the Academy of Sciences-of the Belorussian SSR I. N. Serzhanin for assist— . ing with the collection of material and with the writing of the book, and also to my colleagues while the work was done, notably to Cand. Biol. Sci. E. A. Borovik for help with the work, for reading through the manuscript,.and for valuable advice. • THE BIOLOGY AND DISTRIBUTION OF THE EUROPEAN EEL S,y-stemwtic Position and Distribution The European eel belongs to the( Anguillifarnesorder. ^^r^, o1-^v ^em- bers of this order have no pelvic fins, while some forms, such as the Myraenidae, have lost their pectoral fins also. On the basis of this fact some authors have called this order the Apodes. The present-day fauna includes 24 families of the Anguilliformes, num- bering about 300 species, which consist almost entirely of tropical marine forms. Only members of the Anguillidae family, which contains only a single genus -- the freshwater eels (Anguillashaw.), migrate to fresh water for forage'. I consider that the name freshwater does not correspond to the specific. biological characteristics of the genus Anguilla for all species of eels of this genus are connected with the sea in their origin and reproduction. Most individuals of each speciesforage in the sea and only a few of them migrate to fresh waters for foraging. It would be better to call them diadroinous, but since the name freshwater has long been established in the literature the term will be used hereafter in this book. There is no general agreement regarding the number of species of fresh- water eels. Gunther (170) distinguishes 25 species, Schmidt (1925) and Ege (1939) 20 species, and Berg about 10 species. Besides the European and American eels, this genus also contains six other species found in the Indian Ocean and 12 species in the Pacific Ocean. Of the 12 Pacific species 7 are. found in the waters of the Malay Archipelago and on the northern coast of New Guinea (Schmidt., 1932). Schmidt (1913) based his classification of the eels of Eiarope, America and Japan on the number of vertebrae and the number of rays in the anal fin (Table 1). TABLE 1. Meristic Features Eels tioc.no nymeR aonaboom 5— thicno noemouos .2_ oaaamore BHA Or-40 3 cpelnee er—ao 3 cpenoce et- angUilla . 178-249 215 111 --119 114,7 japonica . 200-253 220 112 -- I I 9 115,8 •4. rostrata . 167-229 190 103-111 107,8 KEY: 1) Species 2) Number.of rays in anal fin 3) From - to 4) Mean 5) Number of vertebrae The same classification has also been used by Walter (1910), Kuznetsov (1915), Ehrenbaum (1930), Eckman (1932), Suvorov (1948), Nikorskii (1950), Kokhenko (1954, 1958), Bertin (1956) and others. Considering the close sim- ilarity between the European, American and Japanese eels both in their morpho- logical structure and in their mode of life, some workers, including Berg 0949) and Shmidt (1947) regard them as subspecies of the same species.