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21. Karyotypes of three species of molossid bats (Molossidae, Chiroptera) from India and western Africa

Creator:
Sreepada, K. S., Koubínová, Darina, Konečný, Adam, Koubek, Petr, Ráb, Petr, Rábová, Marie, and Zima, Jan
Type:
article and TEXT
Subject:
karyotype evolution and chromosome banding
Language:
English
Description:
Conventional and G- banded karyotypes are reported for three species of molossid bats from India (Chaerephon plicatus) and Senegal (Ch. pumilus, Mops condylurus). The chromosome diploid number 2n = 48 and the number of chromosomal arms FN = 54 were recorded, similarly as in the previous published reports on karyology of molossid bats from Thailand, East Malaysia, and Africa. A synopsis of karyotypes of bats of the family Molossidae is presented with comments on their chromosomal evolution.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/

22. Karyotypic relationships of the Tatra vole (Microtus tatricus)

Creator:
Martínková, Natália, Nová, Petra, Sablina, Olga V., Graphodatsky, Alexander S., and Zima, Jan
Type:
article and TEXT
Subject:
chromosomes, banding pattern, phylogeny, M. subterraneus, M. gregalis, and M. afghanus
Language:
English
Description:
This study reports for the first time the banding pattern on chromosomes of the Tatra vole, Microtus tatricus, as revealed by G-, C-, and Ag-NOR staining procedures. The banded karyotype of M. tatricus was compared with Microtus (Terricola) subterraneus, M. (Stenocranius) gregalis, and M. (Blanfordimys) aghanus. The karyotype of M. tatricus possesses highly derived features, e.g., the low diploid number of chromosomes or unique combinations of arms in the biarmed autosomes. It is almost impossible to find clear relationships of M. tatricus with other extant vole species from the point of view of comparative karyology. The karyotypic changes in voles are apparently not accompanied by adequate divergence in morphological and genetic traits.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/

25. Metabolic rate, thermoregulation and distribution of greater long-tailed hamster (Cricetulus triton) in China

Creator:
Wang, De-Hua, Wang, Zu-Wang, Zima, Jan, Griffiths, Huw I., Burda, Hynek, and Sedláček, František
Type:
article and TEXT
Subject:
greater long-tailed hamster, Cricetulus triton, basal metabolic rate, BMR, thermoregulation, ecophysiology, and distribution
Language:
English
Description:
Metabolic rate, body temperature, and thermal conductance were determined in the greater long-tailed hamster (Cricetulus triton) at a temperature range of 5-36 °C. Oxygen consumption was measured by using a closed circuit respirometer. The thermal neutral zone was 39-34 °C. Within a temperature range of 5-31 °C hamsters could maintain a stable body temperature at a mean of 36.7±0.1 °C. Mean basal metabolic rate within thermal neutrality was 1.23±0.02 ml O2/g.h. Total thermal conductance was maintained within a temperature range of 5-15 °C (mean = 0.12±0.00 ml O2/g.h °C). The ecophysiological properties of the greater long-tailed hamster were: (1) a higher metabolic rate than predicted by the allometric scaling equation for eutherian mammals, but lower than that predicted for all rodents and slightly higher than predicted for cricetid rodents; (2) the body temperature was relatively low; (3) thermal conductance was relatively higher than predicted on the basis of body weight. All these characteristics are closely related to the species' life style (i.e. a burrowing, solitary, nocturnal species that feeds mainly on crop seeds and a small fraction of young crop shoots and insects). Greater long-tailed hamsters are primarily distributed in the northern Yangtse River area of China and cannot survive in extremely dr and alpine areas. We propose that the ecophysiological characteristics of the species might constrain its distribution and range extension into extreme deserts, high altitudes and cold areas.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/

26. Metabolism in four rodent species from Ordox arid environment in Inner Mongolia, China

Creator:
Bao, Wei-Dong, Wang, De-Hua, Wang, Zu-Wang, Zima, Jan, Griffiths, Huw I., Burda, Hynek, and Sedláček, František
Type:
article and TEXT
Subject:
rodent, metabolic rate, adaptation, and Ordos Plateau
Language:
English
Description:
A comparative study of resting metabolic rate was conducted for the temperature range 10-37 °C for four rodent species, northern three-toed jerboa (Dipus sagitta) (body mass, Mb 79.2±6.8 g, n = 25), midday gerbil (Meriones meridianus) (Mb = 45.0±8.1 g, n = 10), desert hamster (Phodopus roborovskii) (Mb = 15.4±2.9 g, n = 26, and striped hamster (Cricetulus barabensis) (Mb = 24.8±4.0 g, n = 7) in the Ordos desert in summer (July), 1997. The minimum resting metabolic rates were 1.14±0.25 ml O2/g.h for three-toed jerboa, 1.35±0.3 ml O2/g.h for midday gerbil, 2.98±0.65 ml O2/g.h for desert hamster, and 2.75±0.37 ml O2/g.h for striped hamster. The thermal neutral zones (TNZ) were wide in the three desert species that was 26~37 °C in jerboa, 26~35 °C in gerbil, and 24~34 °C in desert hamster, respectively. For the non-desert species, striped hamster, it was 26~30 °C. The results do not confirm the hypothesis that desert rodents generally have lower metabolic levels than non-desert species. The high metabolic rates of these four rodent species were interpreted to be influenced by the stable availability of food resources and low environmental temperature in the Ordos Plateau. our results partly support the hypothesis that the metabolism characteristics are determined by food resources and environment temperature for animals living in arid regions.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/

27. Morphology and karyology of two populations of the woodland dormouse Graphiurus murinus in the Eastern Cape, South Africa

Creator:
Kryštufek, Boris, Haberl, Werner, Baxter, Rod M., and Zima, Jan
Type:
article and TEXT
Subject:
African dormice, skull, molars, baculum, morphometrics, and karyotype
Language:
English
Description:
We compared cranial, dental, bacular and chromosomal variables between a population of Graphiurus murinus collected in riverine forest in the Andries Vosloo Kudu Reserve (AVKR) near Grahamstown (N= 32), and another from Afromontane forest at Hobbiton on Hogsback (HH), in the Amathole Mountains (N=21), Eastern Cape, South Africa. AVKR dormice were significantly larger in 13 out of a total of 23 cranial dimensions and they had a relatively longer rostrum. The 4th upper premolar was clearly longer and the tip of the baculum broader in the sample from HH. Discriminant function analyses of cranial and dental parameters perfectly separated the two samples. The karyotypes were the same at both localities (2n= 46; NFa = 92) but differed from previously reported karyotypes of Graphiurus species from Africa.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/

28. Muskrat (Ondatra zibethicus) demography and spatial structure in reservoirs in central Russia

Creator:
Gorshkov, Yurii A., Pudovkin, Andrey V., Zima, Jan, Griffiths, Huw I., Burda, Hynek, and Sedláček, František
Type:
article and TEXT
Subject:
muskrat, reservoirs, population structure, radioactive labelling, and age groups
Language:
English
Description:
We studied the demography and spatial structure of the muskrat population at the Nizhnekamsk Reservoir in central Russia. 45Ca radioactive prenatal labelling of muskrats was performed over a period of eight years. A total of 3,876 infividual muskrats were captured from a 12 km2 experimental plot and analysed on the basis of age, sex and presence of radioactivity. During the first year of life, the highest mortality was among muskrats from the latest litter, whilst during the second year of life it was amongst individuals from the earlier litters. Spring and autumn muskrat migration were studied and we observed a cyclical type of spatial structuring within the population. The proportion of individuals migrating in autumn varied from 18-57%, but significant differences in the migratory activities of different age groups were not observed. We found several tendencies throughout the eight years: a decrease in the proportion of the first litter (not overwintering), an increase in the proportion of third litters, and a decrease in the proportion of yearlings born in the first litter - we assume these represent responses to flooding.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/

29. Nonshivering thermogenesis in four rodent species from Kubuqi desert, Inner Mongolia, China

Creator:
Bao, Wei-Dong, Wang, De-Hua, Wang, Zu-Wang, Zima, Jan, Griffiths, Huw I., Burda, Hynek, and Sedláček, František
Type:
article and TEXT
Subject:
nonshivering thermogenesis, rodent species, and Ordos Plateau
Language:
English
Description:
We examined the capacity for nonshivering thermogenesis in four rodent species residing in the Ordos Plateau of Inner Mongolia. Nonshivering thermogenesis (NST, maximum NST minus resting metabolic rate) was determined for northern three-toed jerboas (Dipus sagitta), midday gerbils (Meriones meridianus), desert hamsters (Phodopus roborovskii), and striped hamsters (Cricetulus barabensis) in spring (May), summer (July, and autumn (OCtober) captured in the Kubuqi desert in 1997. NST was induced by norepinephrine (NE) and measured by using the closed-circuit respirometer at 27 °C. Our results showed significant increases from summer to autumn in NST for the four species. NST capacities were 0.52±0.27 ml O2/g0.73.h (n = 7) in summer and 2.49±1.29 (n = 6) in autumn for jerboas, 1.61±0.74 (n = 6) in summer and 3.26±1.35 (n = 5) in autumn for gerbils, 3.62±0.75 (n = 5) in summer and 9.71±2.81 (n = 6) in autumn for desert hamsters, and 6.81±3.02 (n = 8) in summer and 11.23±2.77 (n = 8) in autumn for striped hamsters. These results suggest that small mammals living in the inland arid region on Ordos Plateau adapt to their extreme environment physiologically by adjusting their thermogenic capacities to cope with the dramatic seasonal temperature fluctuations.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/

30. oestrus of female gerbils, Meriones unguiculatus, is indicated by locomotor activity and influenced by male presence

Creator:
Weinandy, René, Hofmann, Sylvia, Gattermann, Rolf, Zima, Jan, Griffiths, Huw I., Burda, Hynek, and Sedláček, František
Type:
article and TEXT
Subject:
locomotor activity, vasectomised males, oestrus cycle, and female aggression
Language:
English
Description:
Mongolian gerbils are territorial and live in family groups with established, stable male-female pairs. The objectives of this study were to investigate whether locomotor activity indicates female receptivity, and to evaluate the impact of a male on the stability of the female sexual cycle. To prevent gravidity, males were sterilised by vasectomy. Nevertheless, they behaved like intact males, displayed copulatory behaviour, and had normal mean serum testosterone levels of 1.1±0.2 ng/ml. Oestrus caused modulations in the activity pattern and hence influenced locomotor activity; female receptivity was reflected by an advance in the onset of activity. Male presence led to prolonged and irregular oestrus cycles in females. Three pairs were stable and nearly no attacks occurred for nine months. However, in four pairs, females suddenly attacked males. Males displayed flight and appeasement behaviours, but two died within 24 hours, and two were severely injured and had to be separated. Two of these females were paired again to other vasectomised males, but killed their cagemates after 3.5 and 12.5 weeks, respectively. In total, six of nine pairs were disrupted by female aggression, four males were killed and two males were separated but presumably would have otherwise died. Females presumably detected male infertility by repeated unsuccessful matings without sperm transmission and/or by physical impairments due to repeated pseudopregnancy. As a result they no longer invested in pair bonds that would eventually diminish their reproductive fitness.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/