Data/hora: 12/06/2024 09:35:02

Provedor de dados: | Institutional Archive of Ifreme (ArchiMer)
País: | France

Título:

Estimation des capacités comportementales des larves de poissons et leurs implications pour la phase larvaire : un cas d’étude des espèces démersales de Méditerranée Nord-Occidentale

Exploring the behavioral abilities of fish larvae and their relevance for the larval phase : a case study of temperate, demersal fish species in the Northwestern Mediterranean Sea

Autores: | Faillettaz, Robin.
Data: | 2015-11-05
Ano: | 2015
Resumo: | Most coastal fish species have a bipartite life history, with a demersal phase as juvenile and adult and a pelagic larval phase. Dispersal is often limited to this pelagic phase, which is also the phase experiencing the highest mortality rates. Predicting the connectivity between populations remains difficult because not all processes determining larval fish survival and transport during the pelagic phase are understood. Besides the environmental conditions that may influence the journey of fish larvae in the open ocean, these tiny organisms possess high behavioural abilities (swimming, orientating, etc.) that have the potential to shape their dispersal. However, the vast majority of in situ observations of these behaviours have been conducted in tropical environments and very little data exists on temperate Perciformes fish larvae. In this dissertation, we aim to describe the ecology and behavioural abilities of fish larvae from the Mediterranean Sea, a temperate environment where they have never been studied. The first part of this dissertation describes the distribution of young fish larvae along an inshore-offshore transect crossing an hydrological front. We also describe their diel vertical migration and predatoravoidance behaviour. The high-frequency imaging techniques used to capture their distribution at miscroscale generated huge amount of data. It lead us to modify an automatic classification method to reduce the time required to processes these kind of data. The second part focuses on the settlement phase, when fish larvae come back to the coast at the end of their pelagic journey. To shed light on the factors influencing the settlement process, we monitored the supply of fish larvae to a coastal habitat, on a weekly basis for three years and at higher frequency over shorter periods of time. Additionally, we tested the in situ orientation abilities of the most abundant species, focusing on large scale orientation mechanisms. In the laboratory, we measured the swimming speeds of several species, including the ones tested for orientation. Then, we implemented these observed behaviours in a biophysical model to explore their combined influence on settlement rate. To finish, we discuss on how larval fish behaviour may influence survival throughout the pelagic larval phase and insist on the importance of considering behaviour to improve larval dispersal models.
Tipo: | Text
Idioma: | Francês

Identificador:

https://archimer.ifremer.fr/doc/00634/74655/74555.pdf

https://archimer.ifremer.fr/doc/00634/74655/

Editor: | Université Paris 06
Formato: | application/pdf

Fonte:

info:eu-repo/semantics/openAccess

restricted use