Holarctic Marmots as a factor of Biodiversity.
Rumiantsev V.Yu;, Nikol'skii A.A. & Brandler O.V. eds.,
Abstracts, 3d Conference on Marmots (Cheboksary, Russia, 25-30 August 1997),
Moscow ABF 1997, 216p. : 178-179.


THE SUBSPECIES AND INTERPOPULATION DIFFERENCES OF THE GREY MARMOT BACULUM


S.B. Pole

Kazakh Antiplague Research Institute, Almaty, Kazakhstan


The pilot researshes of the morphological structure of the grey marmot baculum within the spesies area showed some indications of clinal variability in the west-east direction which was manifected in the simplified bone structure, reduced shaft curve and in the elevated position of the blade towards the shaft axis as well as in the smaller size of the blade, the number and shape of blade denticles (Pole, Bibilkov, 1988, 1992).

The present paper gives the results of the comparative statistic analysis of the morphologial structure of the 85 baculums in adult animals of the grey marmots of the Tien-Shan and Altai subspecis (the table).

The Tien-Shan subspecies is represented by the samples from the Aksai (16 animals), Arpa (10), Transili (6), Ketmen (5), Kokpak (21) and Onarcha (4) populations and the Altai subspecies - by the Cetral Kazarstan (7), Tarbagatai (4), Saur-Ukok (4) and the Sailyugem (8) populations.

The subspecies differences between the Tien-Shan and Altai marmots prove to be statistically valid according to 8 out of the 13 compared indications.

The Tien-Shan marmot obviously surpasses the Altai marmot in the full baculun size, the length and the width of blade, the base width and in the number of blad denticles, but at the same time it obviously is inferior to it in the base length and the enlarged base index. Practically there are no differnces as far as the shaft length, width and the shaft massive index are concerned. As for the value of the base deviation from the shaft axis the differences in the two subspesies appear to be invalid mainly due to tbe high degree of the variability of this indication. On the whole, the average of the value of tbe base deviation from the shaft axis in both the subspecies does not exceed 0.3 mm which is several times less than that of the M. bobac or M. sibirica.

The analysis of the interpopulation variability within the Tien-Shan subspecies seems to confirm the clinal character of the full baculum size, the base length, the base width and the enlarged base index, the blade length and the blade width as well as the number of blade denticles. So the westmost populations (the Aksai and the Arps populations) appear to surpass the eastmost population (the Ketmen population) in the above indications. Populations within the Altai subspecies seem to be more homogmeous in the above mentioned indications. However, tbe Sailyugem sample is obviously inferior to the Central Kazakhstan sample in the full sizes, the shaft curve depth and the enlarged base index.

It is interesting to point out that marmots from the Central Kazakhstan (area bordering on the M. bobac populations) seem to have maximum indications of the enlarged base index, whereas in marmots from the Aksai, Arpa and the Onarcha populatúons (areas bordering on the M. caudata populations) indications of this index appear to be the minimum ones which probably is the result of the interspecies hybridization.

Table.
Comparative morphological charactecistic of the grey marmot baculum in the Tien-Shan and Altai subspecies

Baculum indicationsTien Shan subspeciesAltai subspeciesVariability validity student's criterion
Full baculum size (mm)4.65±0.094.43±0.072.0
Base length (mm)2.01±0.032.22±0.044.2
Base width1.64±0.031.35±0.062.9
Enlarged base index1.26±0.051.68±0.065.4
Shaft length (mm)1.92±0.041.95±0.050.5
Shaft width (mm)0.35±0.010.65±0.020.0
Shaft massive index0.34±0.010.33±0.020.5
Blade length1.95±0.121.57±0.062.8
Blade width (mm)1.28±0.051.00±0.053.9
Number of blade denticle3.48±0.481.79±0.482.5
Including those on the left2.18±0.291.43±0.371.6
Including those on the right1.30±0.200.36±0.143.8
Base deviation from the shaft axis (mm)0.03±0.050.06±0.010.25

The Tien-Shan subspecies is represented by the samples from the Aksai (16 animals), Arpa (10), Transili (6), Ketmen (5), Kokpak (21) and Onarcha (4) populations and the Altai one - by the Central Kazakhstan (7), Tarbagatai (4), Saur-Ukok (4) and the Sailyugem (8) populations.


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