KARYOTYPIC CHARACTERIZATION AND NEW GEOGRAPHICAL RECORD OF Salinomys delicatus (RODENTIA, CRICETIDAE, SIGMODONTINAE).

C. LANZONE,; R.A. OJEDA,; S. ALBANESE,; D. RODRÍGUEZ; M. DACAR

MASTOZOOLOGí­A NEOTROPICAL

Año: 2005 vol. 12 p. 257 - 260

0327-9383

The delicate mouse, Salinomys delicatus, is a rare species among phyllotines. It presents a narrow distribution in the central aridlands of Argentina and high specialization to saline and xeric habitats. We collected this species in the Pipanaco’s salt basin in the Province of Catamarca, Argentina and belongs to the northern Monte desert. The present record of S. delicatus extends the known distribution of this species approximately 270 km to the northwest. The karyotype of the delicate mouse is composed of 2N = 18 and FN = 32; all chromosome elements are biarmed. The pair one is metacentric, pairs two and three are submetacentric, and the remaining chromosomes are metacentric. The first three pairs stand out from the rest because of their large size; the following three pairs are medium-sized, and the last three pairs are small sized. This karyotype comprises the lowest diploid number known among phyllotines. This results are discussed in relationship with early hypothesis or chromosome evolution for the tribe.