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Titolo:
Seasonal arrival patterns of juvenile freshwater eels (Anguilla spp.) in New Zealand
Autore:
Jellyman, DJ; Chisnall, BL; Bonnett, ML; Sykes, JRE;
Indirizzi:
Natl Inst Water & Atmospher Res Ltd, Christchurch, New Zealand Natl Inst Water & Atmospher Res Ltd Christchurch New Zealand ew Zealand Natl Inst Water & Atmospher Res Ltd, Hamilton, New Zealand Natl Inst Water& Atmospher Res Ltd Hamilton New Zealand n, New Zealand
Titolo Testata:
NEW ZEALAND JOURNAL OF MARINE AND FRESHWATER RESEARCH
fascicolo: 2, volume: 33, anno: 1999,
pagine: 249 - 261
SICI:
0028-8330(199906)33:2<249:SAPOJF>2.0.ZU;2-Z
Fonte:
ISI
Lingua:
ENG
Soggetto:
GLASS-EELS; ELVERS ANGUILLA; AMERICAN EEL; WATER FISH; MIGRATION; TEMPERATURE; ROSTRATA; INVASION; STREAMS; SEA;
Keywords:
glass eels; arrival times; pigmentation; riffles; species proportions;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Citazioni:
36
Recensione:
Indirizzi per estratti:
Indirizzo: Jellyman, DJ Natl Inst Water & Atmospher Res Ltd, POB 8602, Christchurch, New Zealand Natl Inst Water & Atmospher Res Ltd POB 8602 Christchurch New Zealand
Citazione:
D.J. Jellyman et al., "Seasonal arrival patterns of juvenile freshwater eels (Anguilla spp.) in New Zealand", NZ J MAR FR, 33(2), 1999, pp. 249-261

Abstract

The arrival season of glass eels of both New Zealand species of freshwatereel, the shortfinned eel (Anguilla australis (Richardson)) and the longfinned eel (A. dieffenbachii (Gray)), was studied by electric fishing of 13 streams/rivers throughout east and west coasts of both North and South Islands at 14-day intervals. Sites were usually located at the most downstream riffle exposed at low tide, and sampled by single-pass electrofishing. The species composition was dominated by shortfins, with exceptions being west coast sites, one in the North Island and two in the South Island. From a comparison of species proportions in adjacent catchments, it was concluded thatglass eels make choices about entry in particular water-types. As the stage of pigmentation advanced during the arrival season, "early stage" glass eels were defined and densities of these compared to show seasonal arrival patterns-densities were generally low in August, highest in September-October, and declined during November-December. Patterns of arrival varied fr-om almost continuous in some streams to "intermittent" in others. Longfinned glass eels preceded shortfinned glass eels, and probably arrived in the North Island before the South Island; shortfinned glass eels showed the opposite trend. Possible migration routes to New Zealand are discussed.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 05/12/20 alle ore 14:13:07