Spalax ehrenbergi Nehring 1897

Wilson, Don E. & Reeder, DeeAnn, 2005, Order Rodentia - Family Spalacidae, Mammal Species of the World: a Taxonomic and Geographic Reference (3 rd Edition), Volume 2, Baltimore: The Johns Hopkins University Press, pp. 907-926 : 918

Spalax ehrenbergi Nehring 1897

Spalax ehrenbergi Nehring 1897 , Sitzb. Ges. Naturf. Fr. Berlin, (for December, 1897) 178: pl. 2.

Type Locality: Israel, Jaffa.

Vernacular Names: Middle East Blind Mole Rat.

Synonyms: Spalax aegyptiacus Nehring 1898 ; Spalax berytensis Miller 1903 ; Spalax fritschi Nehring 1902 ; Spalax intermedius Nehring 1898 ; Spalax kirgisorum Nehring 1898 ; Spalax nevoi Coskun 1996 ; Spalax tuncelicus Coskun 1996 .

Distribution: Middle East: SE Turkey (Kryštufek and Vohralík, 2001), N Iraq ( Hatt, 1959), Syria, Lebanon, Jordan, and Jaffa, Israel. North Africa: Mediterranean coastal region from west of Nile Delta in N Egypt to N Libyan Cyrenaica ( Lay and Nadler, 1972; Osborn and Helmy, 1980; Ranck, 1968).

Conservation: IUCN – Lower Risk (lc) as Nannospalax ehrenbergi .

Discussion:

A cluster of allopatric or parapatric species, each primarily diagnosed by unique chromosomal traits but lacking strong attendant morphological or other distinguishing features, expresses the current perception of S. ehrenbergi , and the reason it is referred to as the S. ehrenbergi superspecies (see reviews by Nevo, 1991; Nevo et al., 2001; Savič and Nevo, 1990). For more than 30 years, Israeli populations of this "superspecies" have been the subjects of intensive research concerning evolutionary theory and the processes of speciation and adaptive radiation ( Nevo, 1991; Nevo et al., 2001). These studies have resulted in the exclusion of ehrenbergi (as historically recognized) from Israel and its replacement by four newly described species (see accounts of S. carmeli , S. galili , S. golani , and S. judaei ) that Nevo et al. (2001:20) defined as "genetically cohesive, interbreeding reproductive communities, adapted to four different climatic-ecological regimes." Each have parapatric ranges separated by narrow hybrid zones but without introgression (e.g., impaired gametogenesis; Zuccotti et al., 1995; strong selection against unfit hybrids, restricted dispersal of hybrids into parental territories, and lowered fitness of hybrids; see Nevo et al., 2001). The four are defined primarily by chromosomal traits, although each can be also distinguished by subtle distinctions in anatomy of middle ear ossicles ( Burda et al., 1990), baculum ( Simson et al., 1993), mandible ( Corti et al., 1996 a), incisor enamel ( Flynn et al., 1987), and molars ( Butler et al., 1993); morphometrics ( Nevo et al., 1988); genetic patterns ( Ben-Shlomo and Nevo, 1993; Ben-Shlomo et al., 1993, 1996; Nevo and Beiles, 1992; Nevo et al., 1992 a, b, 1993, 1994 a, 1997, 1999); DNA/DNA hybridization ( Catzeflis et al., 1989), and patterns associated with physiology, population structures, and behavior (see additional references in the comprehensive review by Nevo et al., 2001).

Confusingly, Nevo et al. (2001:23) did not use ehrenbergi for any of the four Israeli species they recognized, all described as new, because the formal descriptions are based on chromosomal differences and the holotype of ehrenbergi comes from Jaffa, a place located in a hybrid zone between S. carmeli (2n = 58) and S. judaei (2n = 60). Because the karyotype is unretrievable from the holotype, Nevo et al. (2001) reserve ehrenbergi to designate the superspecies but recognize no species per se. No nomenclatural problem exists for those unwilling to accept Nevo’s species definitions (see Nevo et al., 2001:2), for then S. ehrenbergi is simply a species containing great diversity in chromosomal morphology and other traits. On the other hand, if most populations now sequestered in the superspecies are divided into species in a manner apropos those from Israel, the status of the name ehrenbergi will have to be formally clarified, either by resorting to legal petition that renders it unavailable or by identifying the holotype through genetic analyses based on dry tissue.

Chromosomal, allozymic, and body size data from Jordanian samples of the S. ehrenbergi complex has also revealed the presence of an additional four "putative" species with geographic distributions associated with different habitats and climatic regimes ( Ivanitskaya and Nevo, 1998; Nevo et al., 2000). Significant chromosomal, allozymic, ribosomal and mitochondrial DNA sequences, and dental diversity also characterize samples of S. ehrenbergi from SE Turkey ( Butler et al., 1993; Ivanitskaya et al., 1997; Nevo et al., 1994 b, 1995; Sözen et al., 1999; Suzuki et al., 1996 a).

Chromosomal data from an Egyptian sample were provided by Lay and Nadler (1972), who noted its close similarity to central Israeli specimens based on the shared 2n of 60. However, a multidisciplinary approach reveals that the Egyptian population differs from the Israel species by bacular traits ( Simson et al., 1993), molar variation ( Butler et al., 1993), allozymic diversity ( Nevo et al., 1994 a), cranial morphology ( Ellerman and Morrison-Scott, 1951), behavioral traits, and a different karyotypic complement even though the 2n is 60 (Nevo et al., 1992 c). Nevo et al. (1992 c:431) proposed that the Egyptian "isolate is a recently speciating derivative of the Spalax ehrenbergi superspecies, which possibly evolved, because of the disjunction of the Sinai desert from the Israeli mole rats … 10,000 -20,000 years ago." If the Egyptian population is treated as a separate species (and the same as the Libyan population), aegyptiacus (type locality, Ramleh, near Alexandria; see Ellerman and Morrison-Scott, 1951) is the name that should be applied to this North African segment of the S. ehrenbergi complex.

Record of the S. ehrenbergi complex in Israel goes back at least 1.4 million years years before present, but notable diversification in the superspecies is not evident until the last 120,000 years before present ( Nevo, 1993; see reviews by Tchernov, 1992, 1994, and references cited therein). A Lebanese sample, available from prehistoric Natufian occupation, dates from 10,500 -8,000 years before present ( Churcher, 1994)

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