Spider & prey preserved in amber; oldest known fossil; modern spider hunting methods

The Snark

Dumpster Fire of the Gods
Old Timer
Joined
Aug 8, 2005
Messages
11,044
I'm going to have to question the information in that article. Quoting ScienceDaily (Oct. 8, 2012)
"Aside from showing the first and only fossil evidence of a spider attacking prey in its web, the piece of amber also contains the body of a male spider in the same web. This provides the oldest evidence of social behavior in spiders, which still exists in some species but is fairly rare. Most spiders have solitary, often cannibalistic lives, and males will not hesitate to attack immature species in the same web."
All spiders that reproduce cohabit for a given period of time. This smacks of a (pseudo?) science web page tossing out sensationalism.
 

Ciphor

Arachnoprince
Joined
Sep 2, 2011
Messages
1,640
That is true when the male & female are both mature, briefly cohabiting to allow for courtship or rest, however in this case the spider in the image is juvenile, the male in web mature meaning there is no courtship or mating happening yet.

Now, in some species of spider, the male will stay in a female's web and wait for it to reach maturity, almost staking his claims on the female. A good example of this behavior is Steatoda grossa, known very well for males staking claims on immature females by hanging out and cohabitating the web. For most species however this is not true, if a mature male comes across an immature spiders web, one of 4 scenarios will play out.

1) Immature spider eats male
2) Mature male eats immature spider (typical)
3) Male decides the risk is to great, bails
4) Immature spider decides it is outmatched, abandons home (typical)

There is a lot more going on with spider mating than most realize. Males mature faster to prevent incest, some males are evolved to extreme dimorphism, etc. This is an extraordinary discovery, the sensationalism didn't need any help :) We had no idea social behavior was this old in spiders.

Edit: Forgot to mention Snark, take a look at the image again, this spider eating the wasp is quite small and immature compared to the male, whose large leg you can see on the right side of the image. The juvenile could even be another male! Amazing social display for 100 million years ago.
 
Last edited:

findi

Arachnodemon
Old Timer
Joined
Aug 31, 2009
Messages
698
Hi All,

Thanks for the input.

I had doubts about the social aspects as well...could be, but as we're looking at a mere instant in time, difficult to say with certainty what is going on. Re sensationalism, Science Daily is usually accurate in reporting what has been said/written. I checked an abstract of the original article - http://www.tandfonline.com/doi/abs/10.1080/08912963.2011.640399 - and found the wording, re social behavior, to be the same as reprinted by Sc Daily. I'm guessing that the author provides more info in the article, but I do not have a subscription to the journal. At any rate, I passed it along just for interest, seemed a very unique moment captured so clearly, and impt as it is the only known fossil of a spider attacking prey in a web. Best, Frank
 

The Snark

Dumpster Fire of the Gods
Old Timer
Joined
Aug 8, 2005
Messages
11,044
My gripe with the article is as findi mentioned. Being caught in amber is a snap shot. The tiniest microspan of time. Nothing that any reasonable scientific conclusion would be based upon. The report seems to conclude cohabitation as unusual. Some degree of cohabitation is required or the species wouldn't exist in the first place.
Be all that as it may, it is certainly a remarkable little window into a drama played out so long ago.
 

Ciphor

Arachnoprince
Joined
Sep 2, 2011
Messages
1,640
My gripe with the article is as findi mentioned. Being caught in amber is a snap shot. The tiniest microspan of time. Nothing that any reasonable scientific conclusion would be based upon. The report seems to conclude cohabitation as unusual. Some degree of cohabitation is required or the species wouldn't exist in the first place.
Be all that as it may, it is certainly a remarkable little window into a drama played out so long ago.
It is accurate though none the less. Cohabitation of a mature male and immature spider is completely social, and not normal at all. Very, very few species of spider are social like this. Your mistaking cohabitation of sexually mature specimens with this. They are not comparable.

When the ember is examined, both spiders can be seen holding strands of silk, as well as the prey can be seen entangled in strands of silk.

I want you to think about it. This is an orb weaver. Picture a small immature spider in an orb web eating a parasitic wasp while a large mature male hangs out in the same web. Sap did not force this situation into play, it simply captured it and preserved it.
 

findi

Arachnodemon
Old Timer
Joined
Aug 31, 2009
Messages
698
Hi, Thanks for your input. I imagine/hope that the author went into more detail in the journal article; unfortunately, I only have access to the abstract (way too many full subscriptions already!).

Ciphor's comment worthwhile and could very well be accurate, but spiders are an amazingly complex group of animals, and even today behavior is sometimes misinterpreted at first. There are species that rob webs, others that lure web-owners into an ambush by mimicking a prey item, and so on. Difficult for me to draw any conclusions w/o more info.

Re behavior, many years ago in Costa Rica I observed that large orb-weaving spiders (need to check noes re species) would pull the rear legs from grasshoppers before completely wrapping in silk and biting; these were "lubber" type hoppers, with very powerful legs. When I tossed lightly-built katydids of the same size into the web, the spiders did not bother to remove the rear legs, as (I imagine) there's little chance they would damage web or spider. I need to ask an arachnologist friend about this...could be typical, but I haven't had a chance to check.

Thanks again, best, Frank
 

Ciphor

Arachnoprince
Joined
Sep 2, 2011
Messages
1,640
There are species that rob webs, others that lure web-owners into an ambush by mimicking a prey item, and so on. Difficult for me to draw any conclusions w/o more info.
I have the subscription and it doesn't say much more.

Facebook is a wonderful thing if you know the right friends ^_~

At any rate Frank, This is not a mimetid (pirate spider) or even 2 different species.

These are Facts:

The mature male & immature juvenile are the same species.
The mature male & immature juvenile are both sharing the same orb web
The immature juvenile is in the process of attacking the parasitic wasp that became entangled in the web
The mature male is in very close proximity, and may have also been making a move on the wasp
 

findi

Arachnodemon
Old Timer
Joined
Aug 31, 2009
Messages
698
Hello,

Thanks for the feedback and clearing what was contained in the abstract; if the article establishes that they are the same species, then this is indeed an important find. Best, Frank
 
Top