A cytotaxonomic survey of the genus Melanophryniscus Gallardo, 1961 (Anura: Bufonidae).

BALDO DIEGO; COTICHELLI LEONARDO; PEREYRA MARTÏN; BORTEIRO CLAUDIO; NETTO FLAVIA; KOLENC FRANCISCO; BRUSQUETTI FRANCISCO; BIDAU JUAN CLAUDIO

JOURNAL OF HERPETOLOGY

SOC STUDY AMPHIBIANS REPTILES

Año: 2012 vol. 46 p. 25 - 32

0022-1511

ABSTRACT.?In this work we present a cytogenetic survey of the basal bufonid genus Melanophryniscus that covered 14 of the 25 species currently recognized, representing the three phenetic species groups; the M. moreirae, M. stelzneri, and M. tumifrons groups. All species presented a diploid chromosome complement constituted by 11 biarmed chromosome pairs (2n = 2x = 22; FN = 44). Some remarkable differences were observed between species groups: chromosome pair 4 was metacentric in species of the M. tumifrons group (also with a distinctive C-positive block), but submetacentric in the M. stelzneri group and M. sanmartini (M. moreirae group); pair 5 was submetacentric in M. sanmartini and metacentric in the rest. Chromosome secondary constrictions and Ag-NORs were located either in pair 5, 7 or 8, in the M. tumifrons group, M. sanmartini and M. krauczuki (M. stelzneri group), and the M. stelzneri group respectively; and pair 7 was relatively larger in M. sanmartini and M. krauczuki. Studied cytogenetic characters support the M. tumifrons group and suggest a close relationship between M. krauczuki and M. sanmartini. These results call for a reassessment of species relations within Melanophryniscus under an inclusive phylogenetic study.