Internship Proposal - Master 2

To examine these developmental peculiarities, the intern will first participate in our spiny chromis husbandry by monitoring the spawning events and by sampling eggs from the time of fertilization to hatching. A first part of the work will be to strengthen the developmental table established by our team for the spiny chromis, by sampling eggs daily, to photograph them under a stereomicroscope to describe and illustrate embryo morphology and pigmentation, and to fix them for subsequent histological analyses characterizing embryonic histological development with an emphasis on thyroid follicles and retinas. A second part of this internship will be to evaluate the effects of a pesticide (e.g. chlorpyrifos or glyphosate), on the spiny chromis embryonic development previously described. To do so, we have developed a protocol to rear spiny chromis eggs in small-volume aquarium (e.g., petri dishes), allowing us to conduct ecophysiological and ecotoxicological studies in a convenient laboratory set up. Indeed, we showed that TH endocrine disruption induced by anthropogenic stressors such as pesticides can impair metamorphic changes in marine fishes with a classical life cycle, and the spiny chromis would allow us to evaluate these effects directly on eggs. The studied biomarkers will range from developmental defects to hatchlings swimming speed.

The intern will thus (i) gain knowledge in fish sampling, husbandry, ecophysiology, ecotoxicology, neuroendocrinology, and histology, (ii) develop laboratory and experimental skills in fish bioassays, fish embryonic development, fish swimming speeds, and histology;(iii) practice bioinformatic techniques for analyzing and visualizing data; and (iv) acquire communication skills to present and share scientific results.