Asiatic Herpetological Research

1997

Vol.7, pp. 131- 136

On the Distribution of Coluber ravergieri and Coluber nummifer \nTurkmenistan and the Possible Evolutionary Reasons for their Polymorphism
Boris S. Tuniyev

1Chary A. Atayev 2 and Sakhat M. Shammakov 2

Caucasian State Biosphere Reserve. Sochi, Russia'Institute of Zoology. Turkmenian Academy of Sciences, Ashgahat. Turkmenistan

Abstract.- In Turkmenistan. Coluber ravergieri is found in mesic environments. This species was encountered in

mountainous habitats, where there are springs, streams, and small rivers. Along large, permanent rivers that flow

nummifer is more xerophilous and can tolerateofbutinhabitat,
Turkmenistan.
C. nummifer is not found in waterless regions as
temporary drying-up
riparian
into the desert this species penetrates the desert zone. C.

are typical desert snakes. It has been suggested that the polymorphism found in these two species may be due tomimicry with poisonous snakes. We believe that environmental background matching is the primary function of
the coloration in these species and mimicry may only be considered a secondary explanation.

Key words: Reptilia. Squamata. Colubridae. Coluber ravergieri, C. nummifer, Turkmenistan, polymorphism.

Introduction

cially the availability of water and arboreal or

Two closely related species of snakes. Coluber raver-vegetation.

gieri Menetries.
1

1832 and Coluber nummifer Reuss,

834, were studied in Turkmenistan in Central Asia.

shrubResults

The distribution of these snakes after their divisionColuber ravergieri was found throughout the Kopet-(Schatti and Agasian. 1985) in general is known, but
however the questions of polymorphisms within thedag region from the Chandyr River Valley in theKyurendag Mountains in the southwest to thespecies is of interest. The presence of partial and com-

Chaacha River in the east (Fig. 1) and in Badkhyz inplete melanism in some individuals of the ravergieri-

the far east of Turkmenistan in the Kizilayak district

nummifer complex in the Central Asian region raises aon thespecial interest.

The finding of a specimen similar torange

Amu Darya River. Throughout the speciesin Turkmenistan,

we noted black-headed forms

mountain racer (Coluberand specimens with the typical contrasting colorationravergieri morpha glazunovi) in the Eastern Kopetdag

as well as snakes that were only gray in color (Fig. 2-Mountains and the additional information on the dis-3). It is of special interest that a melanistic specimen
was found in the Eastern Kopetdag (IZT, number free.

theso-called Glazunov's

tribution of both species in

Turkmenistan serve as abasis for the this paper.

Manyshsettlement. Eastern Kopetdag, 04-06-1984,

Coll. Ch. Atayev). This large female had a body length

Methods and Materials
Approximately 30 specimens were collected from1989-1993 throughout Turkmenistan. Scale characters

were analyzed on 18 specimens: some of them are
kept in the collection of the Institute of Zoology of theTurkmenian Academy of Sciences (IZT). and in thecollection of the Caucasian State Biosphere Reserve(CSR), other animals were returned to nature. The

number of scales
around the middle of the body (Sq.). the number ofcharacters examined included theventral (Ventr.) and subcaudal (S.cd.) scales as well as

gender, coloration and scalation of the head and body.

Analysis also included habitat characteristics espe-mmandmm, a tail length (L.cd.) of 22521 rows of scales around the middle of the body (Sq.),(L.) of 730

199 belly scales (Ventr.). 87+1

ventraltailscales(S.cd.). and 9 upper labial scales (Lab.) on each sideof the head. The coloration of the body on the upperside is dark-brown-black (Fig. 4). In side light, there's

seen a darker contrasting coloration, typical for C.
ravergieri. In the front one third of the body, there are
8 transverse light yellow stripes. Separate light-colored scales are present on the dorsal side of the ante-body. The snake is a deep black color
from below. On the laryngeal part of the belly thererior half of theare yellow spots and separate light spots are on ventralscales to scale #47 inclusive (figs. 5-7). Situated very

Asiatic Herpetological ResearchVol. 7, p. 131

1997

KTohto-Bqx&rn (\Figure 1. The distribution of Coluber ravergieri and Coluber nummifer in Turkmenistan: 1. C. ravergieri; 2. C. num1. Danata Village, Kyurendag Ridge (IZT, Coll. Atayev); 2. AckVillage, Chandyr River,Southwestern Kopetdag Mountains (IZT, 10.10.1990; Coll. Atayev); 3. Sayvan Village, Western Kopetdag (IZT,m/fer. Coluber ravergieri:

10.10.1990; Coll. Atayev and CBR, No. 450-452.05.1992; Coll. Tuniyev); 4. Tretiy Birleshik Village, vicinity ofGeoktepe settlement (IZT, 03.10.1966; Coll. Atayev); 6. Phiryuza Canyon, Central Kopetdag (IZT, Coll. Atayev); 7.
Keltechinar River (IZT, Coll. Atayev); Gamy Village (IZT, 1977; Coll. Atayev); 8. Anau Village (IZT, 27.09.1970:Coll. Atayev); 9. Yablonevka Village (Khomustenko, 1985); 10.

Manysh Village, Eastern Kopetdag (IZT,04.06.1984; Coll. Atayev); 11. Kharchinnan River, Eastern Kopetdag; 12. Laensuv River, Khiveabad Village; 13.
Chaacha River (CBR, No. 447-448, 04.1992. Coll. Tuniyev); 14. Khatab Village, Kizilayak region (IZT, 03.05.1977.
Coll. Atayev).

Coluber nummifer: 1 Tashauz, Tahtynsky region (IZT, 1970, Coll. Annayev);2. Keltechinar River (IZT, Coll.
Atayev); 3. Kugitang Mountains, Svintzovy Rudnik (IZT, 1981, Coll. Zakharova).
.

near to Eastern Kopetdag. The presence of melanistic

forms of C. ravergieri in the Eastern Kopetdag andthe western part of Pamiro Alaj underlines the faunis-

attacking. Werner (1983) points out the similarity ofC. nummifer and Yipera palaestina in Israel. Schattiand Agasian ( 1985) describe the mimicry of C. raver-originality of this sector of Kopetdag mountains.

gieri and C. nummifer with Yipera lebetina, V. palaes-

The polymorphism of the species C. ravergieri-

tina,

tic

nummifer complex is of evolutionary interest and has

become a classical example of Batesian mimicry inthe literature. The similarity to Viperids was describedfor different pails of distribution. Lantz (1916) noted
the likeness of young Zamenis ravergieri coloration

with that of adders. In spite of this, Lantz underlinesthat the behavioral

mimicry in young C. ravergieri ispersistent and when in danger instead of fleeing theyV.
xanthina and with Agkistrodon halysintermedins. The presence of black-headed specimens

Asian connect

itwith Boiga trigonatnmand(melanocephala)
Naja naja dwelling there.

in Central

we noted the similarity of these mountainIn fact,racers

withadder snakesinsome regions of theformer Soviet Union. In Armenia, in the Khosrov
Reserve male of C. ravergieri were observed with zigzagdorsal

patterns

similartoYipera

raddei.

Inup in a spiral, thickening neck and especially theRazdan Canyon near Erevan (the village of Zovuni).

back side of the head, hiss for a long time, furiously

we observed C. nummifer similar in appearance tocoil

1997

Asiatic Herpetological Research

Figure 2. A blackheaded specimen of Coluber raver-Vol. 7. p. 133

gieri with a contrasting coloration of the body (IZT.

Figure 3. An uniform grey specimen of C. ravergieriwith an unclear picture of the back side of the body

Keltechinar River. 1990: Coll. Atayev).

and tail (IZT. village Sayvan. 1990; Coll. Atayev)

Figure 4. A melanistic specimen of C. ravergieri (IZT

,Eastern Kopetdag, village Manysh. 04.06.1984; Coll.

Figure 5. A melanistic specimen of C. ravergieri (IZTManysh Village): general view from below.

,Atayev): general view from above.

Figure 6. The head and anterior part of the body of melanistic specimen of C. ravergieri from above (IZT,Figure 7. The head and the anterior part of the body ofC. ravergieri. melanistic specimen from below (IZT.

Manysh Village).

Manysh Village).

1997

Asiatic Herpetological ResearchVol. 7, p. 134

bright with contrasting colors, and in dry. bare footthey are monochrome generally the color ofhills

burnt soil.

The nocturnal species (Echis multisquamatus,Boiga trigonatum, Spalerosophis diadema, Lythorhynchus ridgewayi) are characterized by contrastingcoloration

or withtransverselight(almost white)

an irregular manner. The latterresembles burnt grass or brush and twigs, typical hablocatedstripesinwhere these snakes occur. The nocturnal species
tend to be slow and sluggish in behavior.
itat

We observed the triangular head shape described
Figure 8. A young specimen of Coluber nummifer (IZT
Kugitang Mountains, 1981; Coll. Zakharova).

'.

by Werner in V. Lebetina and Naja oxiana as well asother venomous snakes which we have observed innature (Vipera kaznakovi,V.

dinniki,V.

ursinii.

\'.

similarity

aspis. and Agkistrodon halis). When threatened thesevenomous snakes first try to hide and then take aextended to this species behavioral threat response. In

defensive position characteristic for this species only

Central Asian, young C. nummifer (Fig. 8) look likeyoung V. lebetina {turanicalchernovi), but C. raver-Colubrid

gieri may be only remotely similar to Boiga trigona-observed the triangular head shape character in Turk-tum melanocephala.

menistan in 20 specimens of C. rhodorhachis not tak-The problems of snake mimicry, including C.
ravergieri-nummifer, have been considered by Werner

ing into account whether they were red-stripe animals(forma typica) or cross-banded snakes {formasubadullV.

lebetina

obtusa,andthisifitisnecessary. We can noted similar behavior forsnakes independent of coloration. We

We also observed triangular head shape(1983a. 1983b. 1984. 1986). Beside the likeness incoloration. Werner discusses the matters of behavior,ladacensis).

triangular shape of the head of Colubrid snakes inerosophis diadema.

Israel, postulating Batesian or Mullerian mimicry. The

similarity of C. nummifer and C. ravergieri with ven-

Triangular head shape, coiling, hissing and striking as well as protective coloration are the mecha-

omous snakes in Central Asia is intriguing, especiallynisms for avoiding predation. However, in specialized

models and mimics are considered.

snake predators such as Circaetus gallicus attack is

if the ranges of thein C. karelini, C. atayevi, Boiga trigonatum. and Spal-Wemer"s (1983b) explanation that the evolution ofstimulated by the snake form, irrespective of the col-protective coloration by all snakes in the area is a pre-oration and the shape of the head. One pair of C. galli-cursor to mimicry applies here. Earlier Lantz proposed (1916) that reptiles tend to match dominantcus

environmental color. Sweet (1985)

inanalyzing thepossible Batesian mimicry in Pituophis melanoleucus

and Crotalus viridis, pointed out that phenotypic simi-on the Badkhyz Reserve eats about

1800

V.

lebetina in one summer (pers. comm. L. Simakin).
In the case of the C. ravergieri-nummifer complex

polymorphism (and other colubrid species of Turkmenistan) we believe that environmental backgroundtwo species may be a result of cryptic

matching is the primary function of this coloration foradaptation and not selection for mimicry or only addi-

diurnal snakes. And mimicry may only be considered

because the importance of mimicry varies geo-

as a secondary explanation. The presence of melanis-

larity in thesetivegraphically.
Infact,specimens of C. ravergieri in the mountains ofPamiro Alaj and the Eastern Kopetdag may be related
to adaptive thermoregulation and these higher, cooler
ticdiurnal

thesnakesofTurkmenistan(excluding the burrowing species or the species withlimited surface activity; Typhlops, Ery.x, Eirenis) arelocations.

The black-headedness of C. ravergieri inremarkably similar in appearance as are the nocturnal

the Central Asia may be interpreted as a rudimentaryeach other. The diurnal snakes

state of ancestral melanistic coloration and it can also

speciessimilarto(Vipera lebetina.

Coluber ravergieri. C. nummifer.

halis

caucasicus)

distributedin

theAgkistrodon
mountains and foothills are of gray to brown, rusty
colors with black or dark-brown elements forming
spots or a zig zag pattern. In more mesic areas of themountains (mainly in the upper elevations), snakes are

moresubtle physiological meaning as fora sensing element of daily and seabeing
examplesonal temperature changes. The black-headedness cancarry aincrease the role of pineal complex as a sensing element of solar radiation (Ralph et al, 1979) and in conIt was also
trolling the thermoregulatory behavior.

1997

Asiatic Herpetological ResearchVol. 7. p. 135

noted that the head of black-headed forms of C. ravergieri

emerging of holes were difficult

to see in theshadow of the hole.

AppendixI

Physical and pholidotic characters of Coluber ravergieri from Turkmenistan.
LocationVentr.

Khatab Village, Amu Darya River

217

Anau Village. Eastern Kopetdag
Keltechinar River. Eastern Kopetdag

Keltechinar River. Eastern Kopetdag

Ack Village. Western Kopetdag
Sayvan Village. Western Kopetdag
Turkmenistan
Turkmenistan
Keltechinar River. Eastern Kopetdag
Keltechinar River, Eastern Kopetdag

Chaacha River, Eastern Kopetdag
Chaacha River, Eastern Kopetdag

Chandyr River, Western Kopetdag
Sayvan Village, Western Kopetdag
Western Kopetdag. Sayvan village
Turkmenistan

198

S.cd.

Sq.

Sex

Specimen location

Shammokov. S. 1981. [Reptiles of lowland Turkmeni249stan]. Publishing House "Ylym", Ashkhabad, pp.

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