Az angolna (Anguilla anguilla L.) táplálkozása a Balaton parti övében | Feeding of European eel (Anguilla anguilla L.) in the littoral zone of Lake Balaton
Eel, Anguilla anguilla L. that were introduced into Lake Balaton between 1961 and 1991 have a significant effect on the structure and functioning of the aquatic biota in Lake Balaton. During their accelerating phase, the eel stock competed with many indigenous fish species (e.g. common bream, Abrami...
| Main Authors: | , , , , |
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| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
DE Agrár- és Műszaki Tudományok Centruma
2013
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| Subjects: | |
| Online Access: | https://real.mtak.hu/9107/ https://real.mtak.hu/9107/1/Acs_et.al_Speci_Pisces.Hungarici_2013.pdf http://haltanitarsasag.hu/ph7/Acs_et.al_Pisces.Hungarici_2013.pdf |
| Summary: | Eel, Anguilla anguilla L. that were introduced into Lake Balaton between 1961 and 1991 have a significant effect on the structure and functioning of the aquatic biota in Lake Balaton. During their accelerating phase, the eel stock competed with many indigenous fish species (e.g. common bream, Abramis brama (L.)). However, stocks of most fish species (e.g. zander, Sander lucioperca (L.)) were directly influenced by eels predating their juveniles. Disappearance of many animal species from Lake Balaton could be caused by eels as well (e.g. burbot, Lota lota (L.), weatherfish, Misgurnus fossilis (L.), Danube crayfish, Astacus leptodactylus (Eschscholtz)). From 1991 no more eels were introduced to the lake, and the stock density has been continuously decreasing. Nowadays, density of the stock is only 8–12% of the maximum that was reached in 1991. In this study, we investigated what changes occurred in the feeding habit of eel compared to observations of 1970 and 1980. Based on the results of stomach content analysis of eels carried out during 2010, following conclusions were established: 1, Fish, which is one of the main food items of eel, was usually found alone in the alimentary tract. The ratio of piscivorous eels increased in summer. 2, Mixture of mussels, snails and other benthic organisms were characteristic food of eel along with Amphipod crustaceans that could however occur as pure prey as well. The ratio of these organisms was the largest in spring. 3, Eeel is an omnivore species, which can adapt to food sources of various seasons. | Az 1961 és 1991 között nagy mennyiségben telepített angolna, Anguilla anguilla L. a Balaton anyagforgalmára és élővilágára igen jelentős hatással volt. Az angolnaállomány növekedési fázisában bizonyítottan jelentős konkurenciát jelentett számos őshonos halfaj számára (pl., dévérkeszeg, Abramis brama (L.)), de emellett ivadékfalásával közvetlenül is befolyásolta egyes halfajok állományát (pl. fogassüllő, Sander lucioperca (L.)), illetve ragadozásának több állatfaj Balatonból ... |
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