Heteropoda venatoria (Sparrasidae), like Cupiennius salei (Ctenidae), belongs to the Huntsmen spiders. They do not build any webs but live as sit-and-wait predators. Beyond that, with some exceptions on habitus and lifespan, there is no other information on Heteropoda in contrast to Cupiennius on which, thanks to numerous studies, huge knowledge could be gained during the last decades. Therefore, but also because these two spiders live in similar habitats and in general show similar lifestyles

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... nd though have exceptional differences in size and position of their eyes, it is of great interest to take a closer look on the visual system of Heteropoda. In two behavioural experiments and by measuring the visual fields, first data should be gained. Using a goniometer we measured the expansions of the visual fields of the secondary eyes. It could be shown, that the secondary eyes cover almost all of the spiders surrounding with the AL eyes perceiving the very front of the spider, the PM eyes covering almost the entire upper hemisphere and the PL eyes covering great parts of the spiders' side, especially the backside. As the AM eyes do not reflect incident light, due to the lack of a tapetum, these eyes could not be investigated in this study. Only minor differences in size and form of the visual fields between males and females have been detected. All eyes show overlapping areas between and within the different eye types. In the first behavioural experiment we wanted to find out if Heteropoda shows a visual stimulated behaviour and if it can distinguish between different targets, if it is able to perceive them at all. The spiders were set free in an experimental arena in which, in a first series of experiments, two black paper targets with different widths were simultaneously presented. It could be shown that the wider ones were preferred and that when targets of similar width were presented, an equal number of runs headed towards each. In a second series of experiments only one target was presented. As the number of [...]