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Author Dominoni, D.M.; de Jong, M.; Bellingham, M.; O'Shaughnessy, P.; van Oers, K.; Robinson, J.; Smith, B.; Visser, M.E.; Helm, B.
Title Dose-response effects of light at night on the reproductive physiology of great tits (Parus major): Integrating morphological analyses with candidate gene expression Type Journal Article
Year 2018 Publication Journal of Experimental Zoology. Part A, Ecological and Integrative Physiology Abbreviated Journal J Exp Zool A Ecol Integr Physiol
Volume in press Issue Pages in press
Keywords (up) Animals
Abstract Artificial light at night (ALAN) is increasingly recognized as a potential threat to wildlife and ecosystem health. Among the ecological effects of ALAN, changes in reproductive timing are frequently reported, but the mechanisms underlying this relationship are still poorly understood. Here, we experimentally investigated these mechanisms by assessing dose-dependent photoperiodic responses to ALAN in the great tit (Parus major). We individually exposed photosensitive male birds to one of three nocturnal light levels (0.5, 1.5, and 5 lux), or to a dark control. Subsequent histological and molecular analyses on their testes indicated a dose-dependent reproductive response to ALAN. Specifically, different stages of gonadal growth were activated after exposure to different levels of light at night. mRNA transcript levels of genes linked to the development of germ cells (stra8 and spo11) were increased under 0.5 lux compared to the dark control. The 0.5 and 1.5 lux groups showed slight increases in testis size and transcript levels associated with steroid synthesis (lhr and hsd3b1) and spermatogenesis (fshr, wt1, sox9, and cldn11), although spermatogenesis was not detected in histological analysis. In contrast, all birds under 5 lux had 10 to 30 times larger testes than birds in all other groups, with a parallel strong increase in mRNA transcript levels and clear signs of spermatogenesis. Across treatments, the volume of the testes was generally a good predictor of testicular transcript levels. Overall, our findings indicate that even small changes in nocturnal light intensity can increase, or decrease, effects on the reproductive physiology of wild organisms.
Address GELIFES, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2471-5638 ISBN Medium
Area Expedition Conference
Notes PMID:30058288 Approved no
Call Number GFZ @ kyba @ Serial 1964
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Author Wilson, P.; Thums, M.; Pattiaratchi, C.; Meekan, M.; Pendoley, K.; Fisher, R.; Whiting, S.
Title Artificial light disrupts the nearshore dispersal of neonate flatback turtles Natator depressus Type Journal Article
Year 2018 Publication Marine Ecology Progress Series Abbreviated Journal Mar. Ecol. Prog. Ser.
Volume 600 Issue Pages 179-192
Keywords (up) Animals
Abstract After emerging from nests, neonate sea turtles entering the water are thought to orientate away from shore using wave cues to guide them out to sea. Artificial light may interfere with this process, but the relative importance of natural and anthropogenic cues to the dispersal of hatchlings is unknown. Here, we used acoustic telemetry to track the movement of flatback turtle (Natator depressus) hatchlings dispersing through nearshore waters. Turtles dispersed in the presence and absence of artificial light through a receiver array where a range of oceanographic variables were measured. Turtle tracks were analysed using a full subsets Generalised Additive Mixed Model approach to identify the most important cues influencing the bearing, variance in bearing (a measure of the ability to orientate directly), rate of travel and time spent in the array. Artificial light reduced their swim speed by up to 30%, increased the amount of time spent in nearshore waters (by 50–150%) and increased the variance in bearing (100–180% more variable), regardless of oceanographic conditions. Under ambient conditions, ocean currents affected the bearing of hatchlings as they left the shore, but when light was present, this effect was diminished, showing turtles actively swam against currents in their attempts to move towards light. After accounting for the effects of currents on hatchlings dispersing under ambient conditions, turtles swam offshore by moving perpendicular to the coastline and did not appear to orient into incident wave direction. Overall, light disrupted the dispersal of hatchlings causing them to linger, become disoriented in the near shore and expend energy swimming against ocean currents.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0171-8630 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 1967
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Author Kumar, J.; Malik, S.; Bhardwaj, S.K.; Rani, S.
Title Bright light at night alters the perception of daylength in Indian weaver bird (Ploceus philippinus) Type Journal Article
Year 2018 Publication Journal of Experimental Zoology. Part A, Ecological and Integrative Physiology Abbreviated Journal J Exp Zool A Ecol Integr Physiol
Volume 329 Issue 8-9 Pages 488-496
Keywords (up) Animals
Abstract The brighter nights have posed new challenges to the wild species by affecting their temporal physiology. The present study on Indian weaver bird (Ploceus philippinus) investigated if exposure to bright light at different phases of night affects their clock-mediated daily functions. Birds were placed individually in specially designed activity cages under short days and long nights (8L:16D; L = 100 lux, D < 0.1 lux) for approximately 3 weeks (19 days). Thereafter, they were divided into four groups (n = 6-9), and given approximately 2 lux light either for the entire night (ZT 08-24; zeitgeber time 0 = time of light on; pattern A) or for 4 hr (pattern B), placed in 16 hr night such that its onset coincides with the onset of night (early night group, ZT 08-12), its end with the end of night (late night group, ZT 20-24), or the night was interrupted in the middle (midnight group, ZT 14-18). The results showed that bright light in entire night induced early onset of day activity and fragmented rest at night, however, if given at different phases of night, it made the days longer by delaying end (early night group) or advancing onset of daily activity (late night group). It also suppressed the melatonin levels and increased body temperature. These results suggest that bright light at night alters the perception of daylength and affects the underlying physiology. The findings may be useful in adopting a strategy for use of night light without disturbing species fitness in their environment.
Address Department of Zoology, University of Lucknow, Lucknow, India
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2471-5638 ISBN Medium
Area Expedition Conference
Notes PMID:30043408 Approved no
Call Number GFZ @ kyba @ Serial 1971
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Author Konkal, P.; Ganesh, C.B.
Title Exposure to low or high light intensity affects pituitary-testicular activity in the fish Oreochromis mossambicus Type Journal Article
Year 2018 Publication Aquaculture Abbreviated Journal Aquaculture
Volume 497 Issue Pages 109-116
Keywords (up) Animals
Abstract Light is an important factor for the successful reproduction of most fish. In this investigation, effect of different light intensities on pituitary-testis axis was studied for a period of 21 days, under normal photoperiodic regime in the tilapia Oreochromis mossambicus. The mean numbers of spermatogonia (Sg), primary spermatocytes (Ps), secondary spermatocytes (Ss), early spermatids (Est) and late spermatids (Lst) did not show significant difference between fish exposed to moderate light intensity (MLI) and initial controls or controls, whereas the mean numbers of Sg were significantly lower in fish exposed to low light intensity (LLI) compared to those of initial controls, controls and MLI groups. However, the mean numbers of Ps, Ss, Est and Lst were significantly lower in fish exposed to LLI and high light intensity (HLI) compared to those of other experimental groups. Furthermore, in the pituitary gland, weakly immunoreactive luteinizing hormone (LH) secreting cells were observed in the proximal pars distalis (PPD) region in fish exposed to LLI and HLI in contrast to the intense immunolabelling of these cells in initial controls, controls and MLI groups. The androgen receptors showed diminished immunoreactivity in the Sertoli cells along the seminiferous lobules of the testis in fish exposed to LLI and HLI, whereas the strongly immunoreactive androgen receptors were observed in the Sertoli cells in initial controls, controls and MLI groups. Taken together, these results indicate that long-term exposure to low or high light intensity light suppresses spermatogenetic process and that this inhibition is due to reduced secretory activity of LH cells in the pituitary gland and androgen secretion in the testis of the fish O. mossambicus.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0044-8486 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 1974
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Author Firebaugh, A.; Haynes, K.J.
Title Light pollution may create demographic traps for nocturnal insects Type Journal Article
Year 2018 Publication Basic and Applied Ecology Abbreviated Journal Basic and Applied Ecology
Volume 34 Issue Pages 118-125
Keywords (up) Animals
Abstract Light pollution impacts both intra- and inter-specific interactions, such as interactions between mates and predator–prey interactions. In mobile organisms attracted to artificial lights, the effect of light pollution on these interactions may be intensified. If organisms are repelled by artificial lights, effects of light pollution on intra- and inter-specific interactions may be diminished as organisms move away. However, organisms repelled by artificial lights would likely lose suitable habitat as light pollution expands. Thus, we investigated how light pollution affects both net attraction or repulsion of organisms and effects on intra- and inter-specific interactions. In manipulative field studies using fireflies, we found that Photuris versicolor and Photinus pyralis fireflies were lured to artificial (LED) light at night and that both species were less likely to engage in courtship dialogues (bioluminescent flashing) in light-polluted field plots. Light pollution also lowered the mating success of P. pyralis. P. versicolor is known to prey upon P. pyralis by mimicking the flash patterns of P. pyralis, but we did not find an effect of light pollution on Photuris–Photinus predator–prey interactions. Our study suggests, that for some nocturnal insects, light-polluted areas may act as demographic traps, i.e., areas where immigration exceeds emigration and inhibition of courtship dialogues and mating reduces reproduction. Examining multiple factors affecting population growth in concert is needed to understand and mitigate impacts of light pollution on wildlife.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1439-1791 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 1978
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