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Acceso en línea sin restricciones

Se estudió el comportamiento predador de las ninfas de dos especies de Tegenaria frente a su primera presa potencial. La clase de presa confrontada influye en el grado de actividad de la araña, así como en la variabilidad y el encadenamiento de los actos de su comportamiento predador. La secuencia de caza se interrumpe cuando la cazadora toca a una presa homoespecífica viva; en tanto que las otras presas ofrecidas son finalmente atacadas pero de manera diferente, lo cual indica que en las ninfas sin experiencia la capacidad de discriminación es espontánea. Sin embargo es posible que ciertas experiencias precoces, como la convivencia entre ninfas dentro del ovisaco o la ovofagia, puedan influir sobre las capacidades de discriminación, de ataque y de captura de las ninfas sin experiencia previa en la caza. Español

The predatory behavior of the nymphs of two Tegenaria species was studied when they were exposed for the first time to a potential prey. The kind of prey influenced the activity and the variability of predatory behavior as well as the sequence of behavioral acts. Living conspecific prey were nót bitten by the spiders, as were dead conspecifics and other kind of living prey. Some tactile stimulation might be the cause for the momentary interruption of the attack to living conspecific prey, but to really avoid cannibalism, an escape reaction after contact is necessary. Drosophila were bitten immediately after being touched for the first time and rapidly immobilized with "long hites". With aphids the predatory behavior was somewhat different: they were attacked with "brief hites" only severa! behavioral acts after the first contact. These hites were alternated with other behaviours, and these prey were immobilized much later or not all. These results agree with the hypothesis stating that discrimination is a spontaneous capability among the spiderlings. Nevertheless it is possible that precocious experiences, for instance the coexistence of the nymphes inside the egg sac or the ovophagy, influence the discrimination, the attack and the capture capabilities of the naive spiderlings. Inglés