RESUMO
The Odontophrynus americanus species group is a complex of diploid and tetraploid species hardly distinguished by morphological characters. It currently consists of three allopatric diploid species (i.e. O. cordobae, O. lavillai, and O. maisuma) and one widely distributed tetraploid species (i.e. O. americanus). We herein describe a new diploid allopatric species from campo rupestre, a typical phytophysiognomy of the Espinhaço Range, Brazil. The new species is distinguishable by the diploid complement of 2n = 2x = 22 chromosomes, small to medium-sized dorsal dark brown blotches with low contrast on a light brown background, light mid-dorsal stripe absent or greatly interrupted in most specimens with yellowish coloration as the background of both head and flanks of the body, advertisement call with dominant frequency of 840-1080 Hz, pulse rate of 90.5-106.7 pulses/s, and small tadpoles (TL = 24.30-35.69 mm).
Assuntos
Anuros , Diploide , Animais , Brasil , LarvaRESUMO
We report a comparison of toxic and enzymatic activities of Bothrops alternatus venoms collected from specimens of different regions of Argentina with a pool of these same venoms. We determined lethal, hemorrhagic and pro-coagulant (plasma and fibrinogen) doses, as well as indirect hemolysis, hydrolysis of gelatin and fibrinogen. The electrophoretic pattern of the venoms and that of fibrinogen incubated with each of the venoms was studied by SDS-PAGE. The toxic activities were consistent with those reported for these venoms but with noticeable differences between samples which do not seem related to geographical or climatic characteristics. In some cases the pooled venom showed values close to the individual samples, but it was not representative since at least the half of the venoms (4/9) exhibited very different patterns of toxicity. The potency of some activities in the individual venoms ranged from much higher to much lower than those determined in the pooled venom (0.1 to 3 fold). Not all venoms exhibited thrombin-like activity but all hydrolyzed alpha and beta chains of fibrinogen; however, degradation patterns were not always similar. Variation in activities and toxicities do not seem to be related to geographical or climatic characteristics.