Influence of venom availability on a spider’s prey-choice behaviour – Wullschleger & Nentwig – 2002
- Not known whether optimal theory is applicable in spider venom, especially since they capture a wide range of prey. Therefore running out venom is a possibility.
- C salei spiders are able to control the amount of venom they use in a single bite, possibly snakes that are forced to bite onto a rubber film are not releasing as much as they could.
- Prediction: predicted that the spider would choose prey based on its available venom level, this is such a cool idea because it basically gets the spider to perform with minimal interruption in natural behaviour.
- Method: used 4 different but similar in appearance cockroaches b/c the spiders weren’t used to them, thus eliminates the chance of previous exposure having an effect. Also the cockroaches differed in toxicity sensitivity. Ran multiple experiments looking at different things such as female spiders, juvenile spiders and energy content of cockroaches.
- Results: when spiders had full venom glands they did not discriminate between the cockroaches, but when emptied there was a significant preference for a certain cockroach. Juvenile spiders (7months) also did the same. 10 month old spiders did not differentiate between cockroaches regardless of full or empty glands.
- Discussion: they found that their hypothesis was correct and that spiders put more importance on venom availability rather than energetic content of cockroaches, since they did not discriminate based on available energy but rather how sensitive the cockroach was to their venom.
Al3xandria 