2004

Asiatic Herpetological ResearchVol. 10, pp. 208-214

Genetic Variation Among Agamid Lizards of the Trapelus agilis
Complex in the Caspian-Aral Basin
J. ROBERT MACEY1,2,* AND NATALIA B. ANANJEVA3
1Department of Evolutionary Genomics, Joint Genome Institute, Lawrence Berkeley

National Laboratory, 2800 Mitchell Drive, Walnut Creek, CA 94598-1631, USA
2Museum of Vertebrate Zoology, University of California, Berkeley, CA 94720, USA
3Zoological Institute, Russian Academy of Sciences, St. Petersburg, Russia*To whom correspondence should be addressed: E-mail: jrmacey@lbl.gov
Abstract. - Allozyme variation is examined in eight populations of Trapelus from the Caspian-Aral Basin of the former USSR. Thirty one loci (15 variable) exhibit remarkably low levels of genetic variation with only a Nei's genetic distance of 0.117 across 2500 km. An isolated population on the European side of the Caspian Sea is found to phenetically cluster inside the Asian populations examined, suggesting that it should not be considered taxonomically distinct.
Key words. - Reptilia, Squamata, Agamidae, Trapelus, Central Asia, biogeography, allozyme electrophoresis.

Introduction
The Trapelus agilis complex is distributed on the IranianPlateau and adjacent regions of southwestern Asia, as
well as in the Caspian-Aral Basin to the north in the interior of Asia. Two separate populations of the Trapelus
agilis complex are separated by the Caspian Sea in the
Caspian-Aral Basin (including regions draining to Lake
Balkhash) of the former USSR. One population on theeastern side of the Caspian Sea ranges from western
China, Kazakhstan, and Kirgizistan in the north, toTurkmenistan (Fig. 1), Uzbekistan, and Tadjikstan in thesouth. This Central Asian population is continuous with
Iranian, Afghan, and other southwest Asian populations
referred to Trapelus agilis. On the western side of the
Caspian Sea in Europe a small population occurs in
Chechenia and Dagestan, Russia. The two populations
occurring in the Caspian-Aral Basin are placed either ina separate species, T. sanguinolentus, or subspecies, T.
agilis sanguinolentus. Taxonomic controversy also
exists as to the status of the isolated European population of Trapelus. Some authors consider the European
population to be a distinct subspecies of T. sanguinolentus (T. s. sanguinolentus) with the Central Asian populations being referred to T. s. aralensis (Ananjeva andTsaruk, 1987). Others consider the European and Asian
populations in the Caspian-Aral Basin to be a single
taxon, either T. sanguinolentus (Bannikov et al., 1977)
or T. agilis sanguinolentus (Wermuth, 1967). The focusof this study is on the relative position of the Europeanand Asian populations in the Caspian-Aral Basin. The
Caspian-Aral Basin populations are always grouped© 2004 by Asiatic Herpetological Research

together either as a species or as one or two distinct subspecies relative to the southwest Asian populations
referred to as T. agilis.
Trapelus is an old genus of Agamid lizards with an
Afro-Arabian origin (Macey et al., 2000b). Sequence
divergence between Trapelus species in Africa (Trapelus
savignii), Arabia (T. persicus), the Iranian Plateau (T.
agilis), and the Caspian-Aral Basin (Trapelus sanguinolentus population 6 of this study), which form a clade, is10.7-13.9% for the mitochondrial DNA segment spanning from nad1 to cox1 (Macey et al., 2000b). Applying
the rate of 1.3% change per million years for pairwise
comparisons as calculated for this segment of mitochondrial DNA in agamid lizards of the genus Laudakia(Macey et al., 1998), divergence times among these
species of Trapelus are estimated to be 8.3 to 10.7 million years before present (MYBP). These data suggestthat the genus has been in Asia since the Miocene.
Allozyme data are used to distinguish hypotheses of
early divergence of the European and Asian transCaspian populations into discrete entities, verses colonization of the European side of the Caspian Sea by
western Asian populations. High mountains in the
Caucasus and Elburz ranges prevent colonization of theEuropean population from the south, where a continuous
land connection does exist to Trapelus populations in
Iran. The Caspian-Aral Basin corresponds to much of
the Paratethys Sea, which during the Miocene almost
completely dried up 5-6 MYBP and then returned briefly
in the Pliocene, 3.0-3.5 MYBP (Steininger and Rogl,
1984). Divergence following the early period (5-6
MYBP) when much of the Caspian-Aral Basin wasVol. 10, p. 209

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2004

Figure 1. A Trapelus from Repetek Desert Reserve Station, Repetek (38° 34' N, 63° 11' E), Chardjou Region,
Turkmenistan. The photo was taken in May, 1989. This is a representative of population 5 of this study.

available for colonization, should halt gene flow in thelate Miocene or Pliocene and two discrete populations
are expected to be detected, one in Europe and one in
Asia. Alternatively, a more recent colonization from afounder event, when the Caspian Sea level fluctuated in
the Pleistocene, should have a much later restriction ingene flow and therefore the European population may be
expected to be nested within the Asian population.

Material and Methods
Laboratory Protocols. - Tissues were taken in the field,
immediately frozen in liquid nitrogen, and later transferred to an ultracold freezer and maintained at -80° C.
For analysis of allozymic variation, liver and muscle tissues were homogenized separately. Horizontal starchgel electrophoresis was employed to differentiate variation in 31 presumptive loci. The 31 loci and eight bufferconditions utilized to resolve them are displayed in table
1. Allozymes were stained using standard methods(Harris and Hopkinson, 1976; Murphy et al., 1990;
Richardson et al., 1986; Selander et al., 1971).
Carboxylic ester hydrolase (Dimeric Esterase) was
resolved using 4-methylumbelliferyl acetate as the substrate, Alcohol dehydrogenase (ADH) was resolved

using Trans-2-Hexen-1-ol as the substrate, an unidentified peptidase (PEP-1) was resolved using L-leucyl-Lalanine as the substrate, and Peptidase D (PEP-D) and an
unidentified peptidase (PEP-2) with the use of L-phenylalanyl-L-proline as the substrate. The isozymes, andloci if more than one, were labeled according to theirmigration from anode to cathode.
Specimen Information. - Museum numbers and localities for voucher specimens are presented below.
Acronyms are CAS for California Academy of Sciences,
San Francisco and MVZ for Museum of Vertebrate
Zoology, University of California at Berkeley. Russia:(population 1) Tersko-Kumskaya nizmennast (the lowland between Terek and Kuma Rivers), 15 km WNW(airline) of Voskresenskaya, which is approx. 25 km
NNW of Gudermes (43° 21' N
46° 06' E),
Schelkovskaya District, Chechen-Ingush Autonomous
Republic (CAS 182952, 183032-183038). Kazakhstan:(population 2) Almaty (43° 15' N 76° 57' E), Almaty
Region (MVZ 216014-216016, CAS 183047-183051).
Uzbekistan: (population 3) sand dunes on the west sideof the Surkhan Darya (River), on the Kumkurgan (37°
48' N, 67° 37' E) to Denau (38° 16' N, 67° 54' E) Rd.,
Surkhan Darjinskaya Region (CAS 183004-183006).

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Asiatic Herpetological ResearchVol. 10, p. 210

Table 1. The 31 protein loci scored and the electrophoretic conditions within which they were resolved.
Enzyme or blood protein
Serum albumin
Aconitase hydratase
Adenylate kinase
Alcohol dehydrogenase
Aspartate aminotransferase
Carboxylic ester hydrolase
Creatine kinase
Fructose-bisphosphate aldolase
Glucose-6-phosphate isomerase
Glycerol-3-phosphate dehydrogenase
D-2-Hydroxy-acid dehydrogenase
L-Iditol dehydrogenase
Isocitrate dehydrogenase
L-Lactate dehydrogenase
Malate dehydrogenase
Mannose-6-phosphate isomerase
Peptidase (unidentified 1)
Peptidase D
Peptidase (unidentified 2)
Phosphoglucomutase
Phosphogluconate dehydrogenase
Purine-nucleoside phosphorylase
Pyruvate kinase
Superoxide dismutase

Electrophoretic
abbreviation

E. C. No.

No. of Loci

Tissuea

Conditionsb

AB
ACON
AK
ADH
AAT
EST-Dc
CK
FBA
GPI
G3PDH
HADH
IDDH
IDH
LDH
MDH
MPI
PEP-1
PEP-D
PEP-2
PGM
PGDH
PNP
PK
SOD

4.2.1.3
2.7.4.3
1.1.1.1
2.6.1.1
3.1.1.2.7.3.2
4.1.2.13
5.3.1.9
1.1.1.8
1.1.99.6
1.1.1.14
1.1.1.42
1.1.1.27
1.1.1.37
5.3.1.8
3.4.-.3.4.13.9
3.4.-.5.4.2.2
1.1.1.44
2.4.2.1
2.7.1.40
1.15.1.1

1
1
1
2
1
2
1
2
2
1
1
1
2
2
2
1
1
1
1
1
1
1
1
1

L
L
M
L
L
L
M
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L
L

1
2
2
3
4
1
4
5
4
1
5
5
2
3
6
6
1
7
7
8
6
7
8
4

aTissue abbreviations are: L = liver; M = skeletal muscle.
bElectrophoretic conditions: (1) Lithium-borate/Tris-citrate pH 8.2, 250 v for 6 h (Selander et al., 1971); (2) Amine-citrate (Morpholine) pH 6.0, 250 v for 6 h (Clayton and Tretiak, 1972); (3) Tris-citrate/borate pH 8.7, 250 v for 5 h(Selander et al., 1971); (4) Histidine-citrate pH 7.8, 150 V for 8 hours (Harris and Hopkinson, 1976); (5) Phosphate-citrate pH 7.0, 120 v for 7 h (Selander et al., 1971); (6) Tris-citrate II pH 8.0, 130 v for 8 h (Selander et al., 1971); (7) TrisHCL pH 8.5, 250 v for 4 1/2 h (Selander et al., 1971); (8) Tris-maleate-EDTA pH 7.4, 100 v for 10 h (Selander et al.,1971).
cEST-D = Dimeric Esterase

Turkmenistan: (population 4) SW bank of the Amur
Darya (River), approx. 2 km NE of Nephtezavodsk
which is 30 km WNW of Deynau (39° 15' N, 63° 11' E),
Chardjou Region (CAS 179552-179559); (population 5)
1 km north of Repetek Desert Reserve Station, Repetek(38° 34' N, 63° 11' E), Chardjou Region (CAS 179199179203, 179416-179420), and Repetek Desert Reserve
Station, Repetek (38° 34' N, 63° 11' E), Chardjou
Region (CAS 179331); (population 6) 55 km north of
Ashgabat (37° 57' N, 58° 23' E) on the Ashgabat Bakhardok (38° 46' N, 58° 30' E) Rd. then 21 km WNW
on dirt Rd., Ashgabat Region (CAS 179758-179767);(population 7) Ashgabat (37° 57' N, 58° 23' E),
Ashgabat Region (MVZ 216087-216092); (population
8) near Iolotan’ [Yolotan] (37° 18' N, 62° 21' E), MaryRegion (MVZ 216013).
Data Analysis. - Nei’s (1978) unbiased genetic distanceand Rogers (1972) genetic similarity were calculatedusing BIOSYS-1 (Swofford and Selander, 1981).

Phenetic clustering was constructed using the neighborjoining algorithm (Saitou and Nei, 1987), which does
not require rate uniformity, using PAUP* 4.0 (Swofford,
1999) and Nei’s (1978) unbiased genetic distance.

Results
Variable Loci. - Fifteen of the 31 loci screened show
variation among the sampled populations (Table 2). Up
to five different allelic states are recognized per lociamong populations with no more than four allelic states
being present within a population.
Genetic Distances. - Allozymic variation among sampled populations of Trapelus is surprisingly low (Table3). The two geographically most distant samples, theEuropean side of the Caspian-Aral Basin (West Caspian)and Kazakhstan (Almaty), have a Nei’s (1978) unbiased
genetic distance of only 0.117 across 2500 km. The
highest Nei’s (1978) unbiased genetic distances recov-

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Table 2. Electromorph frequencies for the 15 polymorphic loci from eight populations of Trapelus sampled. Localities
are West Caspian (WCA), Almaty (ALM), Uzbekistan (UZB), Nephtezavodsk (NEP), Repetek (REP), 70 km NW
Ashgabat (NWA), Ashgabat (ASH), Iolotan' (IOL). See text for complete localities of all populations used.
Locus
AK

EST-D-2
CK
FBA-1

FBA-2
GPI-2
HADH
IDDH
IDH-1
LDH-2
MPI
PEP-1
PGM
PGDH

PNP

Electromorph 1-WCA 2-ALM 3-UZB
a
b
c
d
a
b
a
b
a
b
c
d
e
a
b
c
a
b
c
a
b
c
a
b
a
b
a
b
a
b
c
a
b
c
a
b
c
a
b
c
d
a
b

0.125
0.875 0.063
0.938
1.000 0.313
0.688
1.000 1.000

4-NEP

5-REP

6-NWA 7-ASH 8-IOL

0.167
0.667
0.167
1.000

0.938
0.063

0.909
0.091

1.000

0.929
0.071

1.000

1.000

1.000

1.000

1.000

1.000

1.000

0.909
0.091

0.950
0.050
1.000

1.000

1.000

1.000

0.063
0.188
0.750

0.500
0.125
1.000 0.875

1.000

1.000

0.929
0.071

0.500

0.600
0.400
0.150
0.850

0.929
0.071

1.000

1.000

1.000

1.000

0.929
0.071

1.000

1.000
1.000

0.875
0.125

0.313
0.688 1.000

1.000

1.000

1.000 1.000

0.667

1.000

0.818
0.182
0.045
0.864
0.091
1.000

1.000
1.000

0.182
0.818
1.000

0.050
0.950
1.000

0.071
0.929
1.000

1.000
1.000

1.000
0.071
0.929

0.100
0.800
0.100

0.857
0.143

0.150
0.850

1.000

1.000

1.000
1.000

1.000
0.500
0.500

1.000

0.333
1.000 1.000
1.000 1.000

1.000
0.833
0.167

1.000 1.000
0.063
0.938 1.000

1.000

0.375
0.625

0.091
0.909

1.000

1.000

1.000 1.000

0.500
0.500

1.000

0.955
0.045
0.045
0.727
0.227
0.091

0.125
0.875 1.000

1.000

0.063
0.125
0.813

0.333
0.667
1.000

0.063
0.125
0.813
1.000

1.000
1.000
1.000 1.000

0.909
0.091
0.091
0.045
0.773
1.000

1.000
0.950
0.050

1.000
1.000
1.000
1.000
0.500
0.500

Table 3. Matrix of genetic distance and identity coefficients from the eight populations of Trapelus sampled. Nei's unbiased genetic distance (Nei, 1978) is above the diagonal, Rogers genetic similarity (Rogers, 1972) is below the diagonal and sample sizes are on the diagonal. See text for specimen deposition and complete localities of all populations
used.

1. West Caspian (WCA)
2. Almaty (ALM)
3. Uzbekistan (UZB)
4. Nephtezavodsk (NEP)
5. Repetek (REP)
6. 70 km NW Ashgabat (NWA)
7. Ashgabat (ASH)
8. Iolotan' (IOL)

1-WCA 2-ALM 3-UZB

4-NEP

5-REP

6-NWA 7-ASH 8-IOL

8
0.865
0.886
0.927
0.928
0.949
0.939
0.899

0.039
0.102
0.031
8
0.952
0.947
0.957
0.925

0.034
0.094
0.019
0.006
11
0.958
0.963
0.920

0.026
0.094
0.032
0.009
0.002
10
0.964
0.932

0.117
8
0.873
0.872
0.865
0.875
0.873
0.836

0.066
0.088
3
0.910
0.920
0.909
0.931
0.900

0.035
0.108
0.021
0.006
0.001
0.003
7
0.943

0.064
0.145
0.048
0.029
0.026
0.026
0.022
1

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Figure 2. Map of the Caspian-Aral Basin and southwest Asia showing the distribution of the Trapelus agilis complex.
Dots depict populations sampled. Lines connect populations in major areas, West Caspian, Kazakhstan, Uzbekistan
and Turkmenistan. Nei's unbiased genetic distance (Nei 1978) is plotted between areas. The Turkmen populations areaveraged. The western most sample on the west side of the Caspian Sea is population 1 (table 3). The eastern most
sample is Almaty in Kazakhstan (population 2). To the southwest of this sample is the Uzbekistan population (population 3). Four of the Turkmen samples are connected by lines. The most northeastern is population 4 from
Nephtezavodsk and the most southeastern is population 5 from Repetek. The most northwestern is population 6 from70 km NW Ashgabat and the most southwestern is population 7 from Ashgabat. Population 8 from Iolotan' is not included in the average of Turkmen populations because of the low sample size of one and it is distributed between populations 5 and 7.

ered are 0.088-0.145 (note that the highest value is witha sample size of one) between the northwestern population in Kazakhstan (Almaty) and all other populations
sampled in the Caspian-Aral Basin. The European population on the western side of the Caspian Sea is separated from all other populations except the Kazakhstan(Almaty) population by Nei’s (1978) unbiased genetic
distances of 0.026-0.066. The population in Uzbekistan

is distinct from those in Turkmenistan by Nei’s (1978)
unbiased genetic distances of 0.019-0.048.
Mapping these genetic distances on geography
reveals a pattern of isolation by distance in which all distances appear relatively additive (Fig. 2). Clustering ofthese data in a neighbor-joining phenogram and rooting
the tree on the longest path places the Kazakhstan(Almaty) population and Uzbekistan sample in a basal

Vol. 10, p. 213

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2004

Basin at around 1.6 MYBP. This result suggests that
Trapelus did not diverge in the Caspian-Aral Basin until
the Pleistocene, well after the last drying of theParatethys Sea 3.5 MYBP (Steininger and Rogl, 1984).
Comparison to Other Taxa. - One additional genus of
lizard has been sampled from the Caspian-Aral Basin forallozyme variation. The northern populations of thegekkonid genus Mediodactylus from Almaty and theJunggar Depression of China show a minimum of two
fixed differences when compared to a southern population in the Kara Kum Desert (Macey et al., 2000a). This
divergence is greater than those observed among
Trapelus where no fixed differences are detected
between Almaty (population 2) and the Kara Kum
Desert (populations 4-8). Because the Caspian-Aral
Basin has had periods of inundation followed by drying
over the last 6 million years, and the surrounding mountains of the Pamir-Tien Shan are older providing a land
refuge (10 million years old; Abdrakhmatov et al.,1996), taxa in the Caspian-Aral Basin may show different levels of divergence.

Figure 3. Neighbor-joining phenogram rooted on thelongest path. Note that the European population on thewestern side of the Caspian Sea is nested inside the
Asian populations sampled and appears as the sister
population to its nearest Asian population (70 km NW
Ashgabat). Population numbers corresponding to figure
1, and tables 2 and 3 are given adjacent to locality
names.

position. The European (West Caspian) population
appears nested within the Turkmen populations and as
the sister population to its nearest Asian population (70km NW Ashgabat), (Fig. 3). This pattern is consistent
with the observed genetic distances.

Discussion
The Age of Trapelus in the Caspian-Aral Basin. - The
European population of Trapelus is found to cluster phenetically within the Asian populations with little genetic
differentiation, suggesting that these taxa do not represent distinct forms. The low genetic diversity inTrapelus of the Caspian-Aral Basin probably indicates a
recent dispersion of Trapelus throughout the CaspianAral Basin. Nei’s (1978) unbiased genetic distances do
not exceed 0.117 (with the exception of Kazakhstan to
Iolotan’ Turkmenistan with a sample size of one). A very
approximate estimate of divergence time and genetic
distance is 14 million years for a Nei’s D of 1.0 (Maxson
and Maxson, 1979). Given this rate these data suggest adivergence of Trapelus populations in the Caspian-Aral

Taxonomic Recommendations. - Because Trapelus
sanguinolentus in the Caspian-Aral Basin is distinguished from Trapelus agilis of the Iranian Plateau by
10.9% sequence divergence for the mitochondrial DNA
segment spanning from nad1 to cox1 (Macey et al.,2000b), we consider them separate species. No morethan a single fixed difference is observed between populations of Trapelus in the Caspian-Aral Basin.
Therefore, we interpret these populations to be a single
taxon, T. sanguinolentus. Further work comparing populations in Southwest Asia is needed in order to determine the specific status of these populations.

Acknowledgments
This work is LBNL-54654 and was performed under the
auspices of the U.S. Department of Energy, Office of
Biological and Environmental Research, under contract
No. DE-AC03-76SF00098 with the University ofCalifornia, Lawrence Berkeley National Laboratory.
This work was also supported by grants from the
National Geographic Society (4110-89 and 4872-93 to
Theodore J. Papenfuss and J.R.M.), Russian Foundationof Basic Research (N 02-04-48720 to N.B.A.), Scientist
School (NS 1647.2003.4 to N.B.A.), the California
Academy of Sciences and the Museum of Vertebrate
Zoology. We thank Tatjana N. Duysebayeva for tissue
specimens. Nikolai Orlov, Theodore J. Papenfuss,
Sakhat M. Shammakov, and Boris S. Tuniyev aided withfield work. Kraig Adler and Allan Larson provided valuable comments on an earlier draft of the manuscript. The
first author thanks David B. Wake and Margaret F. Smith

2004

Asiatic Herpetological Research

for the opportunity to collect allozymic data at theMuseum of Vertebrate Zoology.

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