striped lynx spider (Oxyopes salticus)I was on a panel a few weeks ago discussing mutations, and what they can and cannot do.  Spider-man was one of the topics, because the sad truth is that the Comics industry has conspired in a G-rated cover-up to hide his terrible, terrible affliction.

Spider-man’s spider webbing talent isn’t what you think it is.  Sure, male spiders do have special appendages on the front of their bodies–they are really noticeable “boxing gloves.”  They actually can be up to 20% of a male spider’s body weight.

Those are not, however, what spiders shoot silk or webbing out of.  These pedipalps have one function. SEX.

That white, sticky stuff Peter Parker is shooting out of his wrist? Um. Yeah.

frame from amazing spiderman #503

This is what guys discovering they are covered with spider jizz look like.

There is a reason that people freak out when he shoots a big blop of splooge at them.

See, spiders have a very odd reproductive system. Male spiders don’t have a penis.  (I don’t know if a side effect of Mr. Parker’s radioactive spider bite was his penis falling off, but that might explain his perpetual whiny attitude.  Even if if he did manage to initially retain his penis, it probably broke off later during mating with Mary Jane.)

Pedipalps are modified appendages at the front of a male spider.  They use these to insert sperm into a female’s body.   To get the sperm out of his gonads in the rear, a male spider creates something called a “sperm web” that he limbos underneath and deposits sperm onto.

He then turns around and “loads” the sperm into his pedipalps, and sets off to find a female and hook up.  Pedipalps are the spider equivalent of a turkey baster.

Don’t see the parallel? Let’s review how Mr. Parker’s “slingers” work.  His arms are modified appendages at the front of his body. He has to “load them” with “fresh wet-fluid.”


“But, Bug Girl!” You say. “You don’t understand the story!” Ok, let’s suppose, for your collective mental sanity, that Mr. Parker is actually shooting spider silk, not nocturnal emissions, at villains.

The business end of a spiderSpider silk glands are located anterior to the anus, and posterior to the gonads.  If the radioactive spider had actually given Peter Parker silk glands? He would shoot webbing out of his taint.

Is that….an improvement?  I can certainly see why Spider-man would prefer to gather up the silk and dispense it from a gizmo on his arm, rather than have a little flap in the back of his leotard.

If you would like to look at male spider pedipalps in action, check out this video.  The naughty part begins at 2:35 — note that it really is very much like a turkey baster in function!


Scientifically Accurate Spider-Man (is not accurate)

Posted by Gwen Pearson

Entomologist. Educator. Writer. NERD.


  1. I love this post; it has always bothered me that no one else seemed to notice where spiders extruded their silk versus Peter Parker’s system of dispersal. Brilliant and hilarious.

  2. This is the most horrifying thing that I have read all day. Awesome!

  3. The location of spinnerets for Mr. Parker made an advert for a South Korean water park very special.
    spiderman revealed!

  4. Daniella Martin July 25, 2012 at 10:16 pm

    My boyfriend passionately argues that “in the ORIGINAL Spiderman, Peter Parker actually designed web-shooters in a lab, and then strapped them to his wrists. These were a result of his scientific and technical skills, mixed with spider DNA.” (
    He says Hollywood goofed up the comic-movie translation, and we both think your elucidation on this aspect is hilarious.

  5. You see Daniella? This is how deep the coverup goes!

    Of course Parker is going to say that. Like he’s really going to confess to being a dickless superhero that shoots web out of his taint??

  6. Daniella Martin July 26, 2012 at 12:32 am

    “In early stories, he carries his extra supplies in a utility belt worn under his costume… Pressing down on the palm-trigger of the web-shooter causes the valve in the nozzle to open wider, expelling the fluid.” Cough. Ahem.


    Have a look at that one for a more “realistic” spider super hero

  8. Since he doesn’t get an exo-skeleton, trachea, book-lungs or extra appendages, I don’t really see the problem with the spinnerets being placed in his palms. You need to show, using the actual DNA involved, how a web shooting taint would be a more probable result of a human-spider genetic meld.
    Also, Spiderman should get a job wrapping pallets for transport.

  9. No, Spider-Man’s webbing isn’t what YOU think it is. :P

    I remember when Spidey used to carry a bunch of different cannisters for distributing certain chemicals, like some sort of Batman.

  10. Half of me is glad beyond words that someone is using this as a way to teach spider anatomy. It’s just the rest that makes me switch to full George Takei mode and exclaim “Oh, MY.”

  11. My theory is that when Spider Man was teenage Spider Boy, he spent a lot of time with his “copulatory organ” in his pedapalp (phantasizing about Mary Jane), so it’s easy to see how he got the shooter idea. Besides not having real spinnerets on his butt, why doesn’t he have venomous fangs to deal with the bad guys? What a wuss!

  12. Though I have a huge respect and admiration for these creatures, the things I don’t know about spiders could fill volumes. Turkey baster? For carrying sperm? Who knew?!! I enjoyed the post — and the education.

  13. This is hilarious! I regularly teach children about spiders, and often teach spider anatomy by painting a picture (in their mind’s eye) of spiderman doing thing’s right. You missed one thing that I often point out: spiders cannot shoot silk. They have no muscles for extruding silk. They can pull it out and attach it to something and move away. They also appear to have a means to get it started by hemolymph pressure, but they still rely on the wind or manually extraction. So, Spider Man needs a flap in their pants (Brunetta & Craig’s phrasing from their book “Spider Silk”), and they need to pull it out.

    Just a few clarifications. The primary function of pedipalps is to manipulate food while eating. The male palps acquire an additional function at maturity. So technically, the pedipalps have two functions, though the male bulb (distal-most segment) has only one. Also, there are only a few species of spider for which the palp regularly breaks off in the female’s epigynum. Although spiders don’t technically have penises, they do have long penis-like appendage on each bulb. Each is called an embolus. An embolus does sometimes – rarely – break off during copulation, largely independently of species. Finally, consider that there is one spider that produces silk in it’s head – the spitting spiders (Scytodidae). The silk they produce behaves as a glue and is ejected through their fangs. They shoot this glue/venom mixture at prey to subdue them from a distance.

  14. There was a really old SMBC comic about this:

    I still love that one

  15. Good Points Joe! I thought about trying to explain that Spider-man needs a cribellum, but decided I had enough shocking revelations in one post :D

  16. The spinnerettes are remnants of legs or leg-like appendages that originally were between the genitalia (segment 8) than the anus (segment 12) of some ur-spider. Even some modern tarantulas can produce silk from setae on their tarsi and as noted above Scytodes can spit silk (fangs are just modified legs) as can a number of mites and spider mites produce silk from their pedipalps. So silk production is a function of the limbs in arachnids (my guess is nitrogenous waste from the nephridial glands) and the Spiderman modus spinnerandy is not as unlikely as you claim. Who knows what homeobox genes get turned on an off when you get injected with venom from radioactive spiders! I think you need to cut wrist-spinning some slack.

  17. And who would read a complex post about hox genes and modified appendages, Dave? Not a lot of people :)

  18. You mean like ?

    Well, I guess that did turn out to be a just-so story, alas.

  19. As far as I know, they are still arguing about who’s right on that one.
    Also, judging from my traffic data, few people read that membracid post :)

  20. […] turns out that the Amazing Spider-Man isn’t so much amazing as just perverted. Bug Girl is on top form explaining why you really don’t want to meet Peter Parker in a dark […]

  21. Peter was just bit by a spider. And he gets the ability of Spider eventually becoming a mutant. So he did not lose his human abilities. In addition to that , he posses the ability of a spider. So , it does not mean that he has to lose him P**is or should eject web from his taint.

    In that case, there is a mutant in X-Men called ICE man. Does he melt when he goes under sun???

    Human body ejects sweat through pores in the skin. Why cant spider man use those pores to eject web, assuming he can generate web in his body.

  22. […] Peter Parker, although Bug Girl has written the definitive essay on what should happen if you are bitten by a radioactive spider. Imagine what would happen if you were bitten by a genetically modified gay male mosquitoes. It […]

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