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Master thesis

Etude du comportement des jeunes stades de grande alose (Alosa alosa) : analyse de vidéos en rivières artificielles

Abstract : Belonging to the Clupeids family, the allis shad (Alosa alosa) is an anadromous fish, classified by the IUCN in 2019 as "Critically Endangered" in France. Biological knowledge of juveniles during their growth phase in freshwater remains very limited. The behavior and use of habitat by juveniles before their migration phase are still very little known. The objective of this study was to characterize the influence of circadian rhythm and ontogenic development on the behavior of YOY Allis shad, 1 to 3 months old, reared in artificial rivers. The placement in the water column, swimming directions, type of swimming and social behaviour were analysed by video. At 54-55 days, the results show changes in behaviour mainly between day and night. Surface swimming activity in the direction of the current, in shoals, seems to be more important during the day. On the other hand, there were more solitary individuals, exploring, maintaining themselves against the current during the night. A clear behavioural change also appeared from 70 days compared to individuals observed between 45 and 65 days. Older individuals no longer seemed to descend the current and were observed close to the bottom, in exploration, while at younger ages it was a behavior of passage, in large groups and in the direction of the current that was mostly observed . Further work on the behavioural ecology of juvenile allis shad could be of interest for the conservation of the species.
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Master thesis
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Contributor : Marie-Pierre Maleyran-Raymond <>
Submitted on : Tuesday, June 15, 2021 - 2:52:56 PM
Last modification on : Tuesday, September 7, 2021 - 3:44:22 PM
Long-term archiving on: : Thursday, September 16, 2021 - 6:48:03 PM


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  • HAL Id : hal-03261156, version 1



Jérémy Egea. Etude du comportement des jeunes stades de grande alose (Alosa alosa) : analyse de vidéos en rivières artificielles. Environmental Sciences. 2020. ⟨hal-03261156⟩



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