A widespread problem: cryptic diversity in the Libyan jird

Abstract

Background: The Libyan jird, Meriones libycus, is described as occurring from Morocco to the Mongolian plateau. Three subspecies are known from morphological determinations but not genetic data. We used museum collection locations to create a niche model of the most likely suitable habitat for this species within its potential extent. Using samples collected from the Kingdom of Saudi Arabia, we examined genetic diversity including available samples from China and Tunisia, providing the first genetic overview of this species. Results: Mitochondrial cytochrome b data showed that genetic differentiation between Arabian and other sampling locations of M. libycus is less than the lineage separation seen in Meriones meridianus and greater than that in Meriones tamariscinus. The Arabian lineage investigated here is clearly distinct from the Chinese Meriones libycus erythrourus and Tunisian Meriones libycus syrius, the latter subspecies being previously suggested to occur in the sampling area. Conclusions: We suggest further investigation to ascertain whether the lineage represented here is Arabian Meriones libycus arimalius or a different lineage entirely. We further question the reliability of previous morphological descriptions for producing specific determinations in Meriones and related taxa.

Systematics and evolution of the libyan jird based on molecular and morphometric data

“…The Cytb genetic distance among species of the genus Meriones ranges from 12.3% to 20.5% (Wang, Zhao, Fang, Liao, & Liu, ). Between subspecies, it is 1.4% in Meriones tamariscinus (Bray et al, ), it ranges from 6.7% to 7.5% in M. meridianus (Bray et al, ) and it ranges from 2.5% to 9.6% in M. persicus (Dianat et al, ). The Cytb genetic distance observed between our three lineages of M. libycus corresponds to those observed between other subspecies of Meriones .…”

“…They showed the Arabian lineage (presumably representing M. l. arimalius ) as clearly distinct from the Chinese M. l. erythrourus and the Tunisian M. l. syrius . The Tunisian and Chinese haplogroups only differ in few mutations, which do not strongly support their recognition as distinct subspecies (Bray et al, ). No molecular study encompassing the whole geographic range of the species was ever carried out.…”

“…It becomes most abundant in unflooded river plains and it is often found close to wadies and dayas, and occasionally in arable land (Granjon, ). Fifteen subspecies were described within this species (Figure ): Meriones libycus libycus Lichtenstein, , M. l. erythrourus Gray, , M. l. caucasius Brandt 1855, M. l. eversmanni Bogdanov 1889, M. l. turfanensis Satunin 1903, M. l. aquilo Thomas, , M. l. syrius Thomas 1919, M. l. maxeratis Heptner, , M. l. marginiae Heptner, , M. l. oxianus Heptner, , M. l. sogdianus Heptner, , M. l. afghanus Pavlinov 1987, M. l. farsi Schlitter and Setzer 1973, M. l. iranensis Goodwin 1939, and M. l. arimalius Cheesman & Hinton, (Boudet, ; Bray, Alagaili, & Bennett, ; Corbet, ; Ellerman, ; Ellerman & Morrison‐Scott, ; Harrison & Bates, ; Kingdon et al, ; Kryštufek & Vohralik, ; Pavlinov et al, ). While some subspecies are reportedly widely distributed (e.g., M. l. libycus, M. l. erythrourus ), others have very restricted ranges and are known only from the vicinity of the type locality (e.g., M. l. marginiae , M. l. oxianus, M. l. sogdianus, M. l. iranensis ).…”

“…Map showing the actual geographical distribution of Meriones libycus (in light gray) and its subspecies (green drawing with numbers) based on Boudet (), Bray et al, (), Corbet (); Ellerman (), Ellerman and Morrison‐Scott (), Kingdon et al, (), Kryštufek & Vohralik, , Pavlinov et al, () and Harrison and Bates (). 1‐ Meriones libycus libycus , 2‐ M. l. erythrourus , 3‐ M. l. caucasius , 4‐ M. l. eversmanni , 5‐ M. l. turfanensis 6‐ M. l. aquilo , 7‐ M. l. syrius , 8‐ M. l. maxeratis , 9‐ M. l. marginae 10‐ M. l. oxianus 11‐ M. l. sogdianus 12‐ M. l. afghanus 13‐ M. l. farsi 14‐ M. l. iranensis 15‐ M. l. arimalius .…”

“…All M. libycus subspecies were recognized on skull features (skull size, rostrum length, tympanic bulla size, zygomatic arch) or coat colors, and descriptions were often based on few specimens (Cheesman & Hinton, 1924;Etemad, 1978;Goodwin, 1938;Gray, 1842;Heptner, 1933;Lichtenstein, 1823;Pavlinov & Rossolimo, 1987;Thomas, 1912). The validity of subspecific taxonomy is under considerable discussion and the phylogenetic relationships among them are uncertain (Bray et al, 2014;Ellerman & Morrison-scott, 1951;Pavlinov et al, 2010). Subspecies have long been a controversial taxonomic rank.…”