This video says about itself:
Arachnid Anatomy (Orb-weaving spider)
23 November 2012
A new spin on the usual anatomy video: field biology! Basic external anatomy of an orb-weaving spider, using a live, wild specimen. This is a Cat-faced Spider (Araneus gemmoides), a common species found near/on buildings in North America. I’ve used this as a model although typically the Garden Spider (Argiope sp.) is used in zoology labs.
Also: I let a giant spider walk on my hand. Ha! But it’s OK, they don’t bite.
This video was produced by C. Ernst, a Teaching Assistant.
From Wildlife Extra:
Southern European Spiders prefer a Harvester meal (Harvester Ant, that is)
The southern European spider, Euryopis episinoides, has a distinct preference for Harvester ants, researchers have discovered, and identify them without the benefit of guidance from their parents.
The young spiderlings innately have a nose for these ants, report Stano Pekár and Manuel Cárdenas of the Masaryk University in the Czech Republic in an article in Springer’s journal The Science of Nature – Naturwissenschaften.
Euryopis episinoides is a tiny, 3mm long spider that only catches ants – in particular members of the Messor group of which there are more than 100 species.
The female conveniently lays her egg sacks close to such ant nests but this is about as much parental care as she gives to her offspring.
Once hatched, the spiderlings fend for themselves and this includes recognising and catching prey, all on their own.
The Czech researchers wanted to find out if the Euryopis episinoides spiderlings’ hunting activities were driven by convenience or truly by an innate preference for Harvester Ants.
They tested how newly hatched spiderlings that had not yet gone on the hunt reacted to the chemical cues left by three types of prey: Harvester Ants, fruit flies and Nylander Ants.
In just under half the instances, the inexperienced spiderlings assumed a hunting position in front of a paper strip carrying the smell of Harvester Ants – even though they had never before had the slightest whiff of this type of ant.
The researchers also tested the reaction of more experienced spiderlings that had been raised on only one type of prey: again either Harvester Ants, fruit flies or Nylander Ants.
They found that food imprinting changed the spiderlings’ innate food preference. This was because the spiderlings more often than not chose the type of prey on which they were raised rather than Harvester Ants.
In another twist, the spiders used in the experiment fared better healthwise when they ate ants rather than fruit flies.
“Our findings suggest that prey preference is genetically based but also affected by the experience with the first meal,” says Pekár. “Such an innate preference enables Euryopis episinoides spiderlings to rapidly gain information about prey and to successfully locate their preferred prey on their own.”
“Innate preference is beneficial as it increases efficiency in prey capture,” adds Cárdenas. “It is, however, important that spiderlings hatch near to a place of high ant occurrence, such as ant paths.”