Calomyscus mystax, Kashkarov, 1925

Don E. Wilson, Russell A. Mittermeier & Thomas E. Lacher, Jr, 2017, Calomyscidae, Handbook of the Mammals of the World – Volume 7 Rodents II, Barcelona: Lynx Edicions, pp. 144-155 : 154

4.

Great Balkhan Brush-tailed Mouse

Calomyscus mystax

French: Calomysque de Kashkarov / German: Turkmenistan-Maushamster / Spanish: Raton de cola de cepillo de Gran Balkan

Other common names: Afghan Mouse-like Hamster, Great Balkhan Calomyscus, Great Balkhan Mouse-tailed Hamster

Taxonomy. Calomyscus mystax Kashkarov, 1925 ,

Bashi-Mugur , Big Balkhan Mts., SW Turkmenistan.

Calomyscus mystax was described as a distinct species based on its smaller ears and narrower skull but considered a subspecies of C. bailwardi in early revisions of the genus. N. N. Vorontsov and colleagues in 1979 elevated it to species status based in part on a karyotype with a 2n = 30 that is now associated with a subspecies of C. elburzensis , a species they considered as a synonym of C. mystax . A. S. Graphodatsky and colleagues in 2000 restricted the distribution of C. mystax to the Great Balkhan Mountains (= Uly Balkan) in Turkmenistan and associated the karyotype with a 2n = 44 and FNa = 46 from specimens from these mountains with this taxon. Multivariate discriminant analysis of morphometric data was consistent with restrictions in distribution and chromosomal variation suggested by Graphodatsky and colleagues. Nevertheless, M. N. Meyer and V. G. Malikov in 2000 described specimens with a 2n = 30 and FNa = 44 from Turkmenistan as C. mystax zykovi. They reported natural hybrids from these brush-tailed mice with a cytotype with a 2n = 44 and FNa = 58, which they described as a new species C. firiusaensts on the northern slopes of Mount Dushak in the central Kopet Dag Mountains of Turkmenistan. They also reported that laboratory crosses between these two cytotypes produced viable offspring in which males were sterile; whereas crosses between the 2n = 30 cytotype and the cytotype (2n = 44 and FNa = 46) found in specimens from the type locality of C. mystax produce viable, fertile offspring of both sexes. Both firiusaensis and zykovi were considered synonyms of C. elburzensis by G. G. Musser and M. D. Carleton in 2005. Phylogeographic analysis of cytochrome-b haplotypes from specimens in the central Kopet Dag Mountains of north-eastern Iran are the sister clade to the haplotype from a specimen from the Great Balkhan Mountains of Turkmenistan suggesting a wider distribution of this taxon than the Great Balkhan Mountains. Molecular phylogenetic analyses place C. mystax as the sister taxon of C. urartensis and within the northern clade with C. grandis and C. elburzensis . Monotypic.

Distribution. Limits of distribution unknown but includes the Great Balkhan Mts of W Turkmenistan and the W & C Kopet Dag of S Turkmenistan and NE Iran.

Descriptive notes. Head—body 70-98 mm, tail 62-104 mm, ear 12-20 mm, hindfoot 16-22 mm. No specific data are available for body weight. The Great Balkhan Brushtailed Mouse has smaller ears than other species, averaging 14-5 mm in height. Condylobasal lengths are 21-3-22-5 mm, and zygomatic breadths are 12-2-12-9 mm. Pelage is ash-gray, with yellowish tinge composed of hairs with darker tips. Top of head and back are dark in color, lighter and more yellowish pelage occurs on sides of face and body, and belly is pure white.

Habitat. Rocky terrain on mountain slopes with sparse vegetation.

Food and Feeding. Seeds and fruits of herbs and shrubs make up the bulk of the diet of the Great Balkhan Brush-tailed Mouse. Parts of flowers, leaves, and stems also contributed an insignificant amount to the stomach contents that have been examined. Invertebrate remains were found in 1% of stomachs examined.

Breeding. Reproductive period of the Great Balkhan Brush-tailed Mouse extends from late March until early June, with two litters produced annually. Litter sizes are 3-5 young, but up to seven embryos have been found. Eyes of young open 18-30 days following birth but 70-9% occurred on day 22. Lower and upper incisors erupt 8-18 days and 10-20 days following birth, respectively. The Great Balkhan Brush-tailed Mouse produces fertile hybrids in the laboratory with forms of Goodwin’s Brush-tailed Mouse ( C. elburzensis ) from the Little Balkhan (2n = 30) and western and central Kopet Dag (2n = 44) mountains.

Activity patterns. No information.

Movements, Home range and Social organization. No information.

Status and Conservation. Classified as Least Concern on The [UCN Red Last.

Bibliography. Akbarirad, Darvish & Aliabadian (2016a), Akbarirad, Darvish, Aliabadian & Kilpatrick (2015), Graphodatsky, Radjabli et al. (1989), Graphodatsky, Sablina et al. (2000), Gromov & Erbajeva (1995), Gromov et al. (1963), Lebedev et al. (1998), Malikov et al. (1999), Meyer & Malikov (1995, 1996, 2000), Musser & Carleton (2005), Norris et al. (2008), Pavlinov & Rossolimo (1998), Sapargeldyev (1984), Vorontsov et al. (1979).

Figures

1. Zagros Mountains Brush-tailed Mouse (Calomyscus bailwardi), 2. Hotson’s Brush-tailed Mouse (Calomyscus hotsoni), 3. Pakistan Brush-tailed Mouse (Calomyscus baluchi), 4. Great Balkhan Brush-tailed Mouse (Calomyscus mystax), 5. Goodwin's Brush-tailed Mouse (Calomyscus elburzensis), 6. Noble Brush-tailed Mouse (Calomyscus grands), 7. Urar Brush-tailed Mouse (Calomyscus urartensis), 8. Syrian Brush-tailed Mouse (Calomyscus tsolovi)

Distribution. Limits of distribution unknown but includes the Great Balkhan Mts of W Turkmenistan and the W & C Kopet Dag of S Turkmenistan and NE Iran.