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Electrophoretic Examination of Lacerta mixta, a Possible Hybrid Species (Sauria, Lacertidae)

1973; The Society for the Study of Amphibians and Reptiles; Volume: 7; Issue: 1 Linguagem: Inglês

10.2307/1562823

1937-2418

Thomas Uzzell, Ilya S. Darevsky,

Spider Taxonomy and Behavior Studies

Lantz and Cyren (1936) suggested that their Lacerta mixta arose as a hybrid between L. derjugini and L. saxicola, an origin that would make it unique among known vertebrate species in having both hybrid origin and two sexes. Crossing experiments and morphological studies of populations of L. mixta lend some support to the hybrid origin hypothesis. In contrast, L. mixta differs from both putative parents in electrophoretic patterns for lactate dehydrogenase, mannosephosphate isomerase, and aspartate aminotransferase, and from at least L. deriugini in two peptidases and glocosephosphate isomerase. In its general lack of heterozygosity at these loci, L. mixta shows no evidence of hybrid origin. * * * Lacerta mixta was described (Mehely, 1909) from a single adult male (SMF 12087) collected by H. Leder near Abastumani, in the Georgian S. S. R. in 1879 (Mertens, 1967). Mdhely believed that the holotype shared many features with both Lacerta saxicola and L. derjugini, especially the latter, and described the specimen as a hybrid between the two species. He proposed the name mixta to indicate the morphological intermediacy of the specimens, proposing the name only because of the possibility that the specimen might represent a distinct taxon. Lantz and Cyren (1936), who reviewed the lizards related to Lacerta saxicola, noted certain similarities of L. mixta to L. armeniaca and L. caucasica, two species they thought conspecific with L. saxicola. They also noted some similarities to L. derjugini, but none that made them believe in a hybrid origin for L. mixta. On the basis of detailed study of the Caucasian rock lizards (Darevsky, 1967), the most probable subspecies of L. saxicola that might have hybridized with L. derjugini to give rise to L. mixta is L. s. parvula. This conclusion reflects both geographical and morphological considerations Lacerta mixta and L. s. parvula have largely contiguous ranges; in fact, L. mixta, L. s. parvula, and L. derjugini can all 3 live in close proximity, although L. derjugini is more a creature of stumps and logs in clearings in woods, whereas L. mixta and especially L. s. parvula are more closely associated with rocks. Polozkhina (1965) and Shimansky (1970) have shown that where L. mixta and L. derjugini co-occur, L. mixta more resembles L. derjugini, and where L. mixta and L. s. parvula co-occur, L. mixta more resembles L. s. parvula. Finally, when females of L. derjugini were mated with males of L. s. parvula, the progeny resembled L. mixta in several features (Darevsky, 1966, 1967). As part of a study using biochemical markers to determine the relations of Caucasian species of Lacerta, we have examined specimens of each of these 3 forms. Specimens of L. s. parvula were collected near Adscuri, 30 km SW of Borjomi; specimens of L. mixta came from Baniskevi Canyon, about 10 km N of Borjomi; specimens of L. derjugini came from Baniskevi Canyon and from Akhaldaba, about 10 km NE of Borjomi; all localities are in the Georgian S. S. R. 'Present address: The Academy of Natural Sciences, 19th and the Parkway, Philadelphia, Pa. 19103.