Eel Biology pp 215-222 | Cite as

Downstream Migration of Silver-Phase Anguillid Eels

  • Alex Haro


Downstream migration of adult anguillid eels in freshwater habitats marks the end of a long, generally slow growth phase, abandonment of a home range, and initiation of a seaward spawning migration. Although different species of Anguilla exhibit variation in characteristics of this migratory phase, some generalized traits in migration are common to most species. For temperate and subtropical species of Anguilla,migratory periods are usually associated with times of year when water temperatures are decreasing and flows are increasing. Species of Anguilla in the northern hemisphere usually emigrate between the months of August and December, while those of the southern hemisphere leave freshwater habitats between January and March. In the northern hemisphere, A. rostrata tends to emigrate earlier at higher latitudes (Fig. 1). However, Tesch (1977) concluded that the migration date of A. anguilla could not be predicted on the basis of geography alone. Onset of the silver migratory phase is generally morphologically characterized in most species of Anguilla as a darkening of dorsal surfaces and fin margins, silvering of lateral integument, enlargement of eye diameter, and an increase in gonad development (Lecomte-Finiger 1990). Other endocrinological changes also occur during metamorphosis (Durif et al. 2000).


Downstream Migration Downstream Movement Hydroelectric Project Slow Growth Phase Selective Tidal Stream Transport 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Boëtius J (1967) Experimental indication of lunar activity in European silver eels, Anguilla anguilla (L.). Medd Dan Fisk-Havunders 6:1–6Google Scholar
  2. Boubée JA, Mitchell CP, Chisnall BL, West DW, Bowman EJ, Haro A (2001) Factors regulating the downstream migration of mature eels (Anguilla spp.) at Aniwhenua Dam, Bay of Plenty, New Zealand. N Z J Mar Freshw Res 35:121–134CrossRefGoogle Scholar
  3. Deelder CL (1954) Factors affecting the migration of the silver eel in Dutch inland waters. J Cons Perm Int Explor Mer 20:177–185Google Scholar
  4. Desrochers D (2001) Etude de la migration des anguilles (Anguilla rostrata) du Saint-Laurent et passe migratoire a anguille au barrage de Chambly - 2000. Milieu,QuébecGoogle Scholar
  5. Dollerup J, Graver CM (1985) Repeated induction of testicular maturation and spermiation, alternating with periods of feeding and growth of silver eels, Anguilla anguilla. Dana 4:19–39Google Scholar
  6. Durif C, Elie P, Dufour S, Marchelidon J, Vidal B (2000) Analysis of morphological and physiological parameters during the silvering process of the European eel (Anguilla anguilla) in the lake of Grand-Lieu. Cybium 24:63–74Google Scholar
  7. Durif C, Elie P, Gosset C, Rives J, Travade F, Larinier M (2002) Behavioral study of downstreammigrating eels by radio-telemetry at a small hydroelectric power plant. Am Fish Soc Symp 33 (in press)Google Scholar
  8. Fontaine YA (1994) Eel silvering: metamorphosis, anticipation, adaptation. Bull Fr P êche Piscic 335:171–186CrossRefGoogle Scholar
  9. Frost WE (1950) The eel fisheries of the River Bann, Northern Ireland, and observations on the age of the silver eels. J Cons Perm Int Explor Mer 16:358–393Google Scholar
  10. Hadderingh RH, Van Aerssen GHFM, De Beijer RFLJ, Van der Velde G (1999) Reaction of silver eels to artificial light sources and water currents: an experimental deflection study. Regul Rivers Res Manag 15:365–371CrossRefGoogle Scholar
  11. Hain JHW (1975) The behaviour of migratory eels, Anguilla rostrata, in response to current, salinity, and lunar period. Helgol Meeresunters 27:211–233CrossRefGoogle Scholar
  12. Hansen LP, Jonsson N, Jonsson B (1995) Factors affecting upstream and downstream migration in anadromous European salmonids and catadromous eel. Papers, ICES Council Meeting, Copenhagen, DenmarkGoogle Scholar
  13. Haraldstad O, Vollestad LA, Jonsson B (1985) Descent of European silver eels, Anguilla anguilla L., in a Norwegian watercourse. J Fish Biol 26:37–41CrossRefGoogle Scholar
  14. Haro A (1989) Thermal preferenda and behavior of Atlantic eels (genus Anguilla) in relation to their spawning migration. PhD dissertation, University of Maine, OronoGoogle Scholar
  15. Haro A, Castro-Santos T (2000) Behavior and passage of silver-phase American eels, Anguilla rostrata (Le Sueur), at a small hydroelectric facility. Dana 12:33–42Google Scholar
  16. Haro A, Castro-Santos T, McLaughlin L, Whalen K, Wipplehauser G (2002) Simulation of the influence of hydroelectric project operation on mortality of American eels. Am Fish Soc Symp 33 (in press)Google Scholar
  17. Helfman GS, Facey DE, Hales LS, Bozeman EL (1987) Reproductive ecology of the American eel. Am Fish Soc Symp 1:42–56Google Scholar
  18. Hvidsten NA (1985) Yield of silver eel and factors affecting downstream migration in the stream Imsa, Norway. Inst Freshw Res Drottningholm Rep 62:75–85Google Scholar
  19. Jessop BM (1987) Migrating American eels in Nova Scotia. Trans Am Fish Soc 116:161–170CrossRefGoogle Scholar
  20. Lecomte-Finiger R (1990) Metamorphose de l’anguille jaune en anguille argentée Anguilla anguilla L. et sa migration catadrome. Ann ée Biol 29:183–194Google Scholar
  21. Lowe RH (1952) The influence of light and other factors on the seaward migration of the silver eel (Anguilla anguilla L.). J Anim Ecol 21:275–309CrossRefGoogle Scholar
  22. Oliveira K (1999) Life history characteristics and strategies of the American eel, Anguilla rostrata. Can J Fish Aquat Sci 56:795–802CrossRefGoogle Scholar
  23. Parker SJ, McCleave JD (1997) Selective tidal stream transport by American eels during homing movements and estuarine migration. J Mar Biol Assoc UK 77:871–889CrossRefGoogle Scholar
  24. Poole WR, Reynolds JD, Moriarty C (1990) Observations on the silver eel migrations of the Burrishoole River system, Ireland,1959 to 1988. Int Rev Gesamten Hydrobiol 75:807–815CrossRefGoogle Scholar
  25. Pursiainen M, Tulonen J (1986) Eel escapement from small forest lakes. Vie Milieu 36:287–290Google Scholar
  26. Sloane RD (1984) Preliminary observations of migrating adult freshwater eels (Anguilla australis australis Richardson) in Tasmania. Aust J Mar Freshw Res 35:471–476CrossRefGoogle Scholar
  27. Smith MW, Saunders JW (1955) The American eel in certain fresh waters of the Maritime Provinces of Canada. J Fish Res Board Can 12:238–269CrossRefGoogle Scholar
  28. Svedang H, Wickström H (1997) Low fat content in female silver eels: indications of insufficient energetic stores for migration and gonadal development. J Fish Biol 50:475–486CrossRefGoogle Scholar
  29. Tesch F-W (1977) The eel.Chapman Hall, LondonCrossRefGoogle Scholar
  30. Tesch F-W (1994) Tracking of silver eels in the Rivers Weser and Elbe. Fischokologie 7:47–59Google Scholar
  31. Therrien J, Verreault G (1998) Evaluation d’un dispositif de dévalaison et des populations d’Anguilles en migration dans la rivi ére Rimouski. Minist ère del Environnement et de la Faune, Direction R égionale du Bas-Saint-Laurent, Service del Am énagement et del Exploitation de la Faune et Groupe Conseil G énivar, QuebecGoogle Scholar
  32. Todd PR (1981) Timing and periodicity of migrating New Zealand freshwater eels. N Z J Mar Freshw Res 15:225–235CrossRefGoogle Scholar
  33. Vollestad LA, Jonsson B, Hvidsten NA, Naesje TF, Haraldstad 0, Ruud-Hansen J (1986) Environmental factors regulating the seaward migration of European silver eels (Anguilla anguilla). Can J Fish Aquat Sci 43:1909–1916CrossRefGoogle Scholar
  34. Watene EM, Boubee JAT, Haro A (2002) Downstream movement of mature eels in the Patea Hydroelectric reservoir, New Zealand. Am Fish Soc Symp 33 (in press) NOTE: Tables not edited here. See hard copy. These are TN, TT, TFN only.Google Scholar

Copyright information

© Springer-Verlag Tokyo 2003

Authors and Affiliations

  • Alex Haro
    • 1
  1. 1.S.O. Conte Anadromous Fish Research Laboratory, Biological Resources DivisionU.S. Geological SurveyTurners FallsUSA

Personalised recommendations