Browsing by Author "Killen, Shaun S."

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    Adaptive effects of parental and developmental environments on offspring survival, growth and phenotype
    (2022) Cortese, Daphne; Crespel, Amelie; Mills, Suzanne C.; Norin, Tommy; Killen, Shaun S.; Beldade, Ricardo
    Phenotypic adjustments to environmental variation are particularly relevant to cope with putative environmental mismatches often imposed by natal dispersal. We used an intergenerational cross-transplant field-based experiment to evaluate the morphological and physiological effects of parental and postsettlement water flow environments on the orange-fin anemonefish Amphiprion chrysopterus through ontogeny (at pre- and postsettlement stages). Offspring born from parents under high water flow had an 18% higher caudal fin aspect ratio (a compound measure of shape) at the presettlement stage, 10% slower growth after settlement, and 55% lower survival after settlement compared to offspring from low water flow parents. At the presettlement stage, caudal fin length was determined by parental caudal fin length. At the postsettlement stage, fish survived equally well with similar phenotypes in both high and low developmental flow environments. However, results suggest potential developmental phenotypic plasticity in caudal fin length, which increases more under low water flow during development. After settlement, growth was the only morphological or physiological trait that was associated with parental water flow, which was lower from parents under high flow, as was survival. These results give important insights into the parental contribution, both genetic and nongenetic, in determining early offspring phenotype and subsequent growth and survival. Our results also suggest that offspring may possess flexibility to cope with a wide range of local environments including those different from their parents. Overall, the findings of this study show the fitness consequences of living in different environments and the likely trade-offs between parental and offspring fitness in a wild population. Read the free Plain Language Summary for this article on the Journal blog.
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    Near-future ocean warming and acidification alter foraging behaviour, locomotion, and metabolic rate in a keystone marine mollusc
    (2020) Horwitz, Rael; Norin, Tommy; Watson, Sue-Ann; Pistevos, Jennifer C. A.; Beldade, Ricardo; Hacquart, Simon; Gattuso, Jean-Pierre; Rodolfo-Metalpa, Riccardo; Vidal-Dupiol, Jeremie; Killen, Shaun S.; Mills, Suzanne C.
    Environmentally-induced changes in fitness are mediated by direct effects on physiology and behaviour, which are tightly linked. We investigated how predicted ocean warming (OW) and acidification (OA) affect key ecological behaviours (locomotion speed and foraging success) and metabolic rate of a keystone marine mollusc, the sea hare Stylocheilus striatus, a specialist grazer of the toxic cyanobacterium Lyngbya majuscula. We acclimated sea hares to OW and/or OA across three developmental stages (metamorphic, juvenile, and adult) or as adults only, and compare these to sea hares maintained under current-day conditions. Generally, locomotion speed and time to locate food were reduced similar to 1.5- to 2-fold when the stressors (OW or OA) were experienced in isolation, but reduced similar to 3-fold when combined. Decision-making was also severely altered, with correct foraging choice nearly 40% lower under combined stressors. Metabolic rate appeared to acclimate to the stressors in isolation, but was significantly elevated under combined stressors. Overall, sea hares that developed under OW and/or OA exhibited a less severe impact, indicating beneficial phenotypic plasticity. Reduced foraging success coupled with increased metabolic demands may impact fitness in this species and highlight potentially large ecological consequences under unabated OW and OA, namely in regulating toxic cyanobacteria blooms on coral reefs.
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    Physiological and behavioural effects of anemone bleaching on symbiont anemonefish in the wild
    (2021) Cortese, Daphne; Norin, Tommy; Beldade, Ricardo; Crespel, Amelie; Killen, Shaun S.; Mills, Suzanne C.
    1. Climate change causes extreme heat waves that have induced worldwide mass coral bleaching. The impacts of temperature-induced bleaching events on the loss of algal endosymbionts in both corals and anemones are well documented. However, the cascading impacts of bleaching on animals that live in association with corals and anemones are understudied.
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