Zebrafish take their cue from temperature but not photoperiod for the seasonal plasticity of thermal performance

Abstract

SUMMARYOrganisms adjust to seasonal variability in the environment by responding to cues that indicate environmental change. As most studies of seasonal phenotypic plasticity test only the effect of a single environmental cue, how animals may integrate information from multiple cues to fine-tune plastic responses remains largely unknown. We examined the interaction between correlated (seasonally matching) and conflicting (seasonally opposite) temperature and photoperiod cues on the acclimation of performance traits in male zebrafish, Danio rerio. We acclimated fish for 8weeks and then tested the change in thermal dependence of maximum burst swimming and feeding rate between 8 and 38°C. We predicted that correlated environmental cues should induce a greater acclimation response than uncorrelated cues. However, we found that only temperature was important for the seasonal acclimation of performance traits in zebrafish. Thermal acclimation shifted the thermal performance curve of both traits. For maximum burst swimming, performance increased for each group near the acclimation temperature and reduced in environments that were far from their acclimation temperature. The feeding rate of cold-acclimated zebrafish was reduced across the test temperature range compared with that of warm-acclimated fish. Our study is the first that has found no effect of the covariation between temperature and photoperiod acclimation cues on locomotor performance in fishes. Our results support the intuitive idea that photoperiod may be a less important seasonal cue for animals living at lower latitudes.

Co-Expression of VAL- and TMT-Opsins Uncovers Ancient Photosensory Interneurons and Motorneurons in the Vertebrate Brain

“…Whereas the prevailing paradigm is that such inner brain opsins are involved in seasonal regulation, some of the investigated species such as zebrafish display little or no overt photoperiodicity [41],[42]. This is compatible with the idea that inner brain opsins also serve other, more fundamental functions in the vertebrate brain.…”

“…In addition to their evolutionary divergence, both teleost species originate from different habitats and display different life styles. Japanese medaka fish encounter strong seasonal (winter/summer) differences and exhibit photoperiod-dependent reproduction cycles [39],[40], whereas subtropical zebrafish use temperature and food availability rather than photoperiod to discriminate between monsoon versus nonmonsoon seasons [41],[42].…”

Swimming with Predators and Pesticides: How Environmental Stressors Affect the Thermal Physiology of Tadpoles

“…Previous studies have demonstrated that changes in the shape or position of thermal performance curves can occur due to acclimation (e.g., [73], [74], [75]) or that thermal performance curves of different locomotor strategies for the same organism can have different shapes (e.g., [46], [76]). In the present study, we demonstrate that the presence of sublethal concentrations of an herbicide and cues from predators can also produce changes in the thermal performance curves and therefore affect how tadpoles respond to environmental temperature changes.…”

Temperature acclimation of mitochondria function from the hearts of a temperate wrasse (Notolabrus celidotus)

“…Once acclimation temperatures were reached, fish were held at their prescribed temperatures for six weeks. The responses of whole-animal performance traits by acclimation in fish can be observed by 4-6 weeks of exposure to the new external condition (Johnston and Lucking, 1978;Hammill et al, 2004;Wilson et al, 2007;Condon et al, 2010). Additionally, mitochondrial oxidative capacities were altered within two weeks of warm and cold acclimation (Bouchard and Guderley, 2003).…”