LAUSR

Abstract Vampyrum spectrum is the largest bat species found in the New World. Few cytogenetic data are available on the species, although the diploid chromosome number is known from a specimen captured in Central America in 1970. The present study provides further data on the cytogenetics of V. spectrum, based on the techniques of C banding, impregnation with silver nitrate (AgNORs), staining with chromomycin A3 (CMA3) and fluorescent in situ hybridization (FISH) with probes for 18S rDNA and telomeric sequences. The species presented 2n = 30 chromosomes and 56 autosomal arms. The C banding revealed blocks of constitutive heterochromatin in the pericentromeric regions of all the chromosomes and subterminal blocks on the short arms of chromosome pairs 5, 6, 8 and 9. The AgNORs were found in the secondary constrictions of the long arm of chromosome pair 1. The CMA3 revealed multiple bands in the chromosomes, which permitted the accurate identification of the different chromosome pairs that constitute the karyotype of the species. FISH with 18S rDNA probes revealed the presence of sites in chromosome pair 1, confirming the AgNOR data, while the telomeric probes revealed terminal sites in all the chromosomes of the karyotype. The study thus permitted the identification of specific regions of the chromosomes of this species not catalogued previously, providing important data for comparative studies with other chiropterans.