caa a22 4500 605514372 CHVBK 20210128100704.0 cr unu---uuuuu 210128e20151201xx s 000 0 eng 10.1007/s00360-015-0926-4 doi (NATIONALLICENCE)springer-10.1007/s00360-015-0926-4 Seasonal adaptation of dwarf hamsters (Genus Phodopus ): differences between species and their geographic origin [Elektronische Daten] [D. Müller, J. Hauer, K. Schöttner, P. Fritzsche, D. Weinert] The genus Phodopus consists of three species—P. campbelli (Pc), P. sungorus (Ps), and P. roborovskii (Pr). They inhabit steppes, semi-deserts, and deserts in continental Asia with a climate changing from a moderate to a hard Continental one with extreme daily and seasonal variations. These different environmental challenges are likely to have consequences for hamsters' morphology, physiology, and behavior. Hamsters of all three species were investigated during the course of the year in the laboratory though using natural lighting and temperature conditions. Motor activity and body temperature were measured continuously, and body mass, testes size, and fur coloration every 1-2weeks. With regard to the pattern of activity, nearly twice as many Pc as Ps hamsters (25 vs. 14%) failed to respond to changes of photoperiod, whereas all Pr hamsters did. Body mass and testes size were high in summer and low in winter, with the biggest relative change in Ps and the lowest in Pr hamsters. Changes of fur coloration were found in Ps hamsters only. All responding animals (that is excluding Pr), exhibited regular torpor bouts during the short winter days. In autumn, seasonal changes started considerably earlier in Ps hamsters. To investigate the putative causes of these different time courses, a further experiment was performed, to identify the critical photoperiod. Hamsters were kept for 10weeks under different photoperiods, changing from 16 to 8h light per day. Motor activity was recorded continuously, to identify responding and non-responding animals. Body mass was measured at the beginning and the end of the experiment, testes mass only at the end. The critical photoperiod was found to be similar in all three species. Though in a further experiment, Pc and Pr hamsters showed a delayed response, whereas the changes in Ps hamsters started immediately following transfer to short-day conditions. The results show that interspecific differences in seasonal adaptation exist, even between the closely related Ps and Pc hamsters, possibly due to different conditions in their natural habitat. Also, the impact of environmental factors like climatic conditions and food resources may differ between species. Springer-Verlag Berlin Heidelberg, 2015 Dwarf hamsters nationallicence Photoperiodism nationallicence Critical photoperiod nationallicence Non-responder nationallicence Motor activity nationallicence Body temperature nationallicence Body mass nationallicence Testes size nationallicence Fur coloration nationallicence Müller D. Institute of Biology/Zoology, Martin Luther University Halle-Wittenberg, Domplatz 4, 06108, Halle, Germany aut Hauer J. Institute of Biology/Zoology, Martin Luther University Halle-Wittenberg, Domplatz 4, 06108, Halle, Germany aut Schöttner K. Institute of Biology/Zoology, Martin Luther University Halle-Wittenberg, Domplatz 4, 06108, Halle, Germany aut Fritzsche P. Institute of Biology/Zoology, Martin Luther University Halle-Wittenberg, Domplatz 4, 06108, Halle, Germany aut Weinert D. Institute of Biology/Zoology, Martin Luther University Halle-Wittenberg, Domplatz 4, 06108, Halle, Germany aut Journal of Comparative Physiology B Springer Berlin Heidelberg 185/8(2015-12-01), 917-930 0174-1578 185:8<917 2015 185 360 https://doi.org/10.1007/s00360-015-0926-4 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00360-015-0926-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Müller D. Institute of Biology/Zoology, Martin Luther University Halle-Wittenberg, Domplatz 4, 06108, Halle, Germany aut NATIONALLICENCE 700 1- Hauer J. Institute of Biology/Zoology, Martin Luther University Halle-Wittenberg, Domplatz 4, 06108, Halle, Germany aut NATIONALLICENCE 700 1- Schöttner K. Institute of Biology/Zoology, Martin Luther University Halle-Wittenberg, Domplatz 4, 06108, Halle, Germany aut NATIONALLICENCE 700 1- Fritzsche P. Institute of Biology/Zoology, Martin Luther University Halle-Wittenberg, Domplatz 4, 06108, Halle, Germany aut NATIONALLICENCE 700 1- Weinert D. Institute of Biology/Zoology, Martin Luther University Halle-Wittenberg, Domplatz 4, 06108, Halle, Germany aut NATIONALLICENCE 773 0- Journal of Comparative Physiology B Springer Berlin Heidelberg 185/8(2015-12-01), 917-930 0174-1578 185:8<917 2015 185 360