Literaturdatenbank
Literaturdatenbank |
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McGlashan, J. K., Spencer, R.-J., & Old, J. M. (2011). Embryonic communication in the nest: metabolic responses of reptilian embryos to developmental rates of siblings. Proceedings of the Royal Society B: Biological Sciences, (Published online before print).
Added by: Admin (29 Jan 2012 12:38:59 UTC) |
| Resource type: Journal Article DOI: 10.1098/rspb.2011.2074 BibTeX citation key: McGlashan2011 View all bibliographic details  |
Categories: General Keywords: Chelidae, Emydura, Emydura macquarii, Physiologie = physiology, Schildkröten = turtles + tortoises, Zeitigung = incubation Creators: McGlashan, Old, Spencer Collection: Proceedings of the Royal Society B: Biological Sciences |
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| Abstract |
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Incubation temperature affects developmental rates and defines many phenotypes and fitness characteristics of reptilian embryos. In turtles, eggs are deposited in layers within the nest, such that thermal gradients create independent developmental conditions for each egg. Despite differences in developmental rate, several studies have revealed unexpected synchronicity in hatching, however, the mechanisms through which synchrony are achieved may be different between species. Here, we examine the phenomenon of synchronous hatching in turtles by assessing proximate mechanisms in an Australian freshwater turtle (Emydura macquarii). We tested whether embryos hatch prematurely or developmentally compensate in response to more advanced embryos in a clutch. We established developmental asynchrony within a clutch of turtle eggs and assessed both metabolic and heart rates throughout incubation in constant and fluctuating temperatures. Turtles appeared to hatch at similar developmental stages, with less-developed embryos in experimental groups responding to the presence of more developed eggs in a clutch by increasing both metabolic and heart rates. Early hatching did not appear to reduce neuromuscular ability at hatching. These results support developmental adjustment mechanisms of the ‘catch-up hypothesis’ for synchronous hatching in E. macquarii and implies some level of embryo–embryo communication. The group environment of a nest strongly supports the development of adaptive communication mechanisms between siblings and the evolution of environmentally cued hatching.
Added by: Admin |