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Host sex and ectoparasite infections of plateau pika [Ochotona curzoniae, Hodgson] on the Qinghai-Tibetan Plateau

100%

Ci H. , Lin G. , Su J. , Cao Y.

Polish Journal of Ecology

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2008

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tom 56

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nr 3

535-539

EN

A total of 449 plateau pika (Ochotona curzoniae Hudgson) individuals were sampled with rattraps from 21 plots (size 1 ha) randomly scattered over the area of the species distribution at the altitude 3275–4807 m a.s.l. in the Qinghai-Tibetan Plateau (West China). Two main ectoparasite species Hypoderma satyrus Brauer and Ixodes crenulatus Neumann of plateau pika were surveyed, and the relations between host sex and parasitism were analyzed. The results were: (i) although not significantly, the infection rate of female young was close to zero and lower than that of male young (6%), while the infection rate of female sub-adults (19%) was contrarily – higher than that of male sub-adults (11%); adult females had significantly higher (41%) infection rate than that of males (18%) (P <0.001); (ii) the parasite infection rates for both males and females increased with increasing age, but female age-groups had obviously steeper slope. We suggested that the differences of body mass, growth rate and home range between males and females had mainly caused the sex-biased parasitism (SBP) of plateau pika at each age stage. Also, due to the higher increases of body mass and maybe as well as of the home range differences between consecutive age-groups, the parasite infections of females became more sensitive to the influences of age than that of males.

2

Host sex and ectoparasite infections of plateau pika (Ochotona curzoniae, Hudson) on the Qinghai-Tibetan Plateau

100%

Ci H. , Lin G. , Su J. , Cao Y.

|

tom Vol. 56, nr 3

535-539

EN

A total of 449 plateau pika (Ochotona curzoniae Hudgson) individuals were sampled with rattraps from 21 plots (size 1 ha) randomly scattered over the area of the species distribution at the altitude 3275-4807 m a.s.l. in the Qinghai-Tibetan Plateau (West China). Two main ectoparasite species Hypoderma satyrus Brauer and Ixodes crenulatus Neumann of plateau pika were surveyed, and the relations between host sex and parasitism were analyzed. The results were: (i) although not significantly, the infection rate of female young was close to zero and lower than that of male young (6%), while the infection rate of female sub-adults (19%) was contrarily - higher than that of male sub-adults (11%); adult females had significantly higher (41%) infection rate than that of males (18%) (P <0.001); (ii) the parasite infection rates for both males and females increased with increasing age, but female age-groups had obviously steeper slope. We suggested that the differences of body mass, growth rate and home range between males and females had mainly caused the sex-biased parasitism (SBP) of plateau pika at each age stage. Also, due to the higher increases of body mass and maybe as well as of the home range differences between consecutive age-groups, the parasite infections of females became more sensitive to the influences of age than that of males.

3

Phylogenetic discontinuity of plateau zokor (myospalax baileyi thomas) populations in qinghai-tibetan plateau

100%

Tang L. , Zhang T. , Lin G. , Su J.

Polish Journal of Ecology

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2010

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tom Vol. 58, nr 1

167-176

EN

Mitochondrial cytochrome b gene sequences and morphological data (body length, hind foot length, etc.) for twelve populations with pairwise distances 27-600 km in Qinghai-Tibetan Plateau (distributed in Qinghai, Gansu and Sichuan Province, and at the altitude 3020-4550 m) in Western China were used to investigate the phylogeographical pattern of Plateau zokor (Myospalax baileyi Thomas). There was a little disparity between mtDNA genetic distance and morphological Euclidean distance on population relationships. However, there is a significant correlation (P <0.001) calculated by Mantel's tests was validated between mtDNA and morphology distances. Analysis of Molecular Variance showed that most of the observed genetic variations occurred between populations, indicating little maternal gene flow between them, as a result of geographical restrictions. Phylogenetic analysis coupled with cluster analysis together showed that the substantial population structuring and phylogenetic discontinuities existed within this species. The evident allopatric population structuring of this subterranean rodent may mostly result from its specialized subterranean excavating behavior with high energy costs, predation from grassland raptors and also the influences of perennial tundra and environmental desiccation in the Qinghai-Tibetan Plateau.

4

Genetic variation and molecular evolution of endangered Kozlov.s pika (Ochotona koslowi Buchner) based on mitochondrial cytochrome b gene

88%

Lin G. , Ci H. , Thirgood S. , Zhang T. , Su J.

Polish Journal of Ecology

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2010

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tom Vol. 58, nr 3

563-568

EN

Kozlov's pika is a rare and endangered lagomorph species with a limited distribution in the southern Kunlun Mountains in western China. Because of its endangered status, Kozlov's pika is considered a priority species for research and conservation action. Genetic variation and molecular evolution of the Kozlov's pika were studied based on a total of 14 individuals from four locations along the eastern boundary between Xinjiang and Tibet province (35.20-36.48[degrees]N, 86.08-83.04[degrees]E) on extremely high elevation (usually over 4800 m a.s.l.). The density of local populations was about 3-4 per ha, living in a typical alpine desert grassland habitat. The complete mitochondrial cytochrome b (cytb) gene was amplified and sequenced. Based on the cytb gene sequences the genetic variation and molecular evolution were analyzed. Unexpected high haplotype diversity (0.956 [plus or minus] 0.045) but low nucleotide diversity (0.00537 [plus or minus] 0.00126) was found, indicating past demographic expansion. Significant partitioning of variance (P <0.01) among populations (46.7%), and within populations (53.3%), indicating low level of genetic differentiations among local populations. Our results gave an optimistic survival status of Kozlov's pika at the genetic level. Bayes Empirical Bayes analysis with model M2a and M8 detected three positively selected amino acid sites at the significance level of 0.05. The mutant types with either or both of the mutations aspartic acid to asparagine and glutamic acid to lysine had higher isoelectric point values. We suggested these mutant types might have biological significance to help individuals to adapt to the extremely high elevation habitats.