Comments on: Killer funnel-web spiders invade Sydney!

By: Nick

Nick — Sun, 16 May 2010 17:58:18 +0000

@Leon I also find it fascinating how it doesn’t effect other mammals only primates the way it does,one gene here or there and this is what you get

But v annoying if it wasn’t for this i wouldn’t fear oz quite so much!

By: Leon

Leon — Sat, 01 May 2010 17:52:58 +0000

It is an interesting and mystifying quirk of nature, Nick. I think most scientists consider the unique sensitivity of the nervous systems of humans and other primates to Sydney funnel-web spider venom (atratoxin) to be just bad luck. it is true that mice, rabbits, and other non-primate mammals are relatively immune to the effects of the venom, requiring many times the dose that will affect humans. However, atratoxin is also quite effective in killing insects, which is certainly why it evolved.

By: Nick

Nick — Sat, 01 May 2010 16:40:02 +0000

watching the video by chance or design,well it is obviously by chance it is so deadly to primates,but very strange how it doesn’t effect other mammals

By: Leon

Leon — Fri, 22 Jan 2010 18:41:39 +0000

Christine:

Thanks for the comments. It is my understanding — correct me if I’m wrong — that although other funnel-webs are found in other areas of Australia, and may be chemically more toxic than the Sydney, Atrax Robustus is the only species that has been associated with human fatalities.

I did look at the MJA review form 2005 while compiling this post.
For the record, the authors of that study analyzed 138 cases of funnel-web bites in which the spider was definitely identified by experts; 77 cases were classified as severe, and antivenom was used in 29. Some of their findings:

- Although definite funnel-web bites occurred in all eastern states and territories of Australia, severe envenomation occurred only in New South Wales and southern Queensland.

- There were 13 deaths (7 in children) all before 1981.

-There were 3 adverse effects in 75 patients who received antivenom.

- There was complete response to antivenom in 97% of expertly identified cases (some of which involved, not. A. robustus, but Hadronyche species).