Léopold GHINTER
BIENVENÜE & PNMI/OFB
Start Date
09/09/2026
End Date
09/09/2026
Characterising the physiological tolerance ranges of fish in nursery habitats
Coastal nursery habitats are essential for the development of many fish species. They are also highly variable environments, where temperature and oxygen availability can change rapidly over the course of a single day. In fish, these two environmental factors act in concert to influence the organism’s energy balance. Temperature influences metabolic requirements, the cells’ capacity to produce ATP and the efficiency of this production, whilst oxygen availability determines the ability to sustain aerobic metabolism. It is therefore the combination of these factors, rather than each considered in isolation, that defines the physiological conditions fish can withstand. The NURSFISH project aims to characterise these limits in several species of juveniles reared in hatcheries. In particular, it will seek to determine under what conditions their maintenance metabolism can still be sustained, how their bioenergetic capacities change with temperature and oxygen availability, and under what conditions their acute tolerance limits are reached. The aim is therefore not merely to assign a critical temperature or oxygen level to a species, but to understand how these various physiological limits interdepend on one another. Combining these factors will enable a better definition of the range of conditions within which the organism can maintain its functioning. To this end, NURSFISH will combine measurements taken at the whole-organism level and at the cellular level. Measurements of metabolism and acute tolerance will help identify the conditions under which basic physiological needs can no longer be fully met, as well as those leading to an acute loss of tolerance. At the cellular level, the project will focus on the mitochondria of the heart and brain, two organs that are highly dependent on a continuous energy supply. Thermal performance curves will be used to determine how mitochondrial respiration, energy production and its efficiency change with temperature. A key aim will be to identify whether certain bioenergetic changes occur before the acute limits observed at the whole-animal level. By integrating these different levels of organisation, NURSFISH will thus seek to define, for each species, a physiological operating range – inspired by the concept of the temperature–oxygen metabolic niche (Ern, 2019) – extending from the maintenance of metabolism to the acute limits of tolerance. These limits will then be compared with the variations in temperature and oxygen levels actually encountered in hatcheries. It will then be possible to estimate the margin between environmental conditions and the physiological thresholds of each species, and to identify situations where this margin becomes particularly narrow. This approach will enable a comparison of the vulnerability of species sharing the same habitat but possessing different physiological capacities. Ultimately, NURSFISH aims to transform complex physiological responses into integrated indicators that can better characterise the functional quality of nursery areas and the environmental conditions likely to compromise it. Ref : Ern, R. (2019). A mechanistic oxygen-and temperature-limited metabolic niche framework. Philosophical Transactions of the Royal Society B: Biological Sciences, 374(1778), 20180540. [av_slideshow img_copyright='left' size='no scaling' control_layout='av-control-default' slider_navigation='av-navigate-arrows av-navigate-dots' nav_visibility_desktop='' nav_arrow_color='' nav_arrow_bg_color='' nav_dots_color='' nav_dot_active_color='' img_copyright_font='' av-desktop-font-img_copyright_font='' av-medium-font-img_copyright_font='' av-small-font-img_copyright_font='' av-mini-font-img_copyright_font='' animation='slide' transition_speed='' autoplay='true' interval='3' img_scale='' img_scale_end='10' img_scale_direction='' img_scale_duration='3' img_scale_opacity='1' conditional_play='' img_scrset='' lazy_loading='enabled' alb_description='' id='' custom_class='easy-slider-text-white' template_class='' av_uid='av-ug0rdpg' sc_version='1.0'] [av_slide id='205730'][/av_slide] [av_slide id='205732'][/av_slide] [av_slide id='205734'][/av_slide] [av_slide id='205736'][/av_slide] [/av_slideshow]Laboratory Members
Contributors
Christophe Lebigre (DECOD – Ifremer)
Loïc Teulier (UMR LEHNA – Université Claude Bernard, Lyon 1)
Damien Roussel (UMR LEHNA – Université Claude Bernard, Lyon 1)
