RESUMEN
Centipedes are part of the diet of several snake species of the genus Bothrops. However, reports on predation of centipedes by snakes are normally incomplete, and important data for natural history studies as the species identification and size of the prey are rarely published. The aim of this work was to report the presence of the centipede Scolopendra viridicornis in the digestive tract of the Amazon pit viper B. atrox. The snake specimen is an immature female from Aripuanã, state of Mato Grosso, Brazil, having a 623 mm snout-vent length. The centipede is an adult Scolopendra viridicornis, estimated to be 190 mm long, and found in the snake's stomach. The success in preying on this large and potentially dangerous centipede could be explained by the snake's dimensions, large enough for overpowering the prey, but still retaining characteristics of youth, such as venom with specific action against specific prey items.
Lacraias fazem parte da dieta de diversas espécies de serpentes do gênero Bothrops. Entretanto, informações importantes para estudos de história natural, como identificação da espécie e tamanho de presas, são raramente publicados. O objetivo desse trabalho é registrar a presença de uma lacraia Scolopendra viridicornis, no trato digestivo de uma jararaca da Amazônia, Bothrops atrox. A serpente estudada é uma fêmea imatura, com 623 mm de comprimento rostro-cloacal, proveniente de Aripuanã, estado de Mato Grosso, Brasil. A lacraia é um adulto de Scolopendra viridicornis parcialmente digerida, com aproximadamente 190 mm de comprimento. O sucesso na predação dessa grande e perigosa presa pode ser explicado pelas dimensões da serpente, que é grande o suficiente para dominar a presa, mas ainda retém características juvenis, como veneno com ação específica em determinados ítens alimentares.
Asunto(s)
Animales , Bothrops/metabolismo , DietaRESUMEN
Snakes that can ingest prey that are proportionally large have high metabolic rates during digestion. This great increase in metabolic rate (specific dynamic action - SDA) may create a significant augment in the animal's body temperature. The present study investigated postprandial thermogenesis in Bothrops moojeni. Briefly, two groups of snakes were fed meals equivalent to 17 ± 3 percent and 32 ± 5 percent of their body weight and were observed for 72 hours, in which thermal images of each snake were taken with an infrared camera in a thermostable environment with a constant air temperature of 30ºC. The results showed a significant increase in snake surface temperature, with a thermal peak between 33 and 36 hours after feeding. The meal size had a great impact on the intensity and duration of the thermogenic response. Such increase in temperature appears to be connected with the huge increase in metabolic rates during digestion of relatively large prey by snakes that feed infrequently. The ecologic implication of the thermogenic response is still not well understood; however, it is possible that its presence could affect behaviors associated with the snake digestion, such as postprandial thermophily.
Asunto(s)
Animales , Bothrops/metabolismo , Digestión , Conducta Alimentaria , Termogénesis/fisiologíaRESUMEN
Two presynaptic phospholipases A2 (PLA2), neuwieditoxin-I (NeuTX-I) and neuwieditoxin-II (NeuTX-II), were isolated from the venom of Bothrops neuwiedi pauloensis (BNP). The venom was fractionated using molecular exclusion HPLC (Protein-Pak 300SW column), followed by reverse phase HPLC (æBondapak C18 column). Tricine-SDS-PAGE in the presence or absence of dithiothreitol showed that NeuTX-I and NeuTX-II had a molecular mass of approximately 14 kDa and 28kDa, respectively. At 10æg/ml, both toxins produced complete neuromuscular blockade in indirectly stimulated chick biventer cervicis isolated preparation without inhibiting the response to acetylcholine, but NeuTX-II reduced the response to KCl by 67.0±8.0 percent (n=3; p<0.05). NeuTX-I and NeuTX-II are probably responsible for the presynaptic neurotoxicity of BNP venom in vitro. In fact, using loose patch clamp technique for mouse phrenic nerve-diaphragm preparation, NeuTX-I produced a calcium-dependent blockade of acetylcholine release and caused appearance of giant miniature end-plate potentials (mepps), indicating a pure presynaptic action. The N-terminal sequence of NeuTX-I was DLVQFGQMILKVAGRSLPKSYGAYGCYCGWGGRGK (71 percent homology with bothropstoxin-II and 54 percent homology with caudoxin) and that of NeuTX-II was SLFEFAKMILEETKRLPFPYYGAYGCYCGWGGQGQPKDAT (92 percent homology with Basp-III and 62 percent homology with crotoxin PLA2). The fact that NeuTX-I has Q-4 (Gln-4) and both toxins have F-5 (Phe-5) and Y-28 (Tyr-28) strongly suggests that NeuTX-I and NeuTX-II are Asp49 PLA2.
Asunto(s)
Animales , Bothrops/metabolismo , Venenos de Crotálidos , Fosfolipasas A/química , Neurotoxinas/envenenamientoRESUMEN
Se estudiaron las actividades edematizante y mionecrótica inducidas por veneno de Bothrops jararaca de Argentina. Para la actividad edematizante se inocularon ratones con distintas dosis de veneno diluído en 0.05 ml de solución fisiológica. La dosis de 0.86 mug/20g ratón provocó un edema del 30 por ciento respecto al miembro opuesto en 1 hora. La evaluación de los efectos mionecróticos se realizó en ratones inoculados en el músculo gastroenemio con 70 mug de veneno em 0.1 ml de solución fisiológica, los que se sacrificaron en distinos tiempos de exprosición. Del área de inoculación se obtuvo material para procesamiento histopatológico. Los animales sacrificados a los 30 y 60 minutos revelaron edema y mionecrosis. Aquellos que se sacrificaron a las tres horas después de la inoculación, edemas de edema y hemorragia, presentaron necrosis e infiltrado inflamatorio.