Mating of the Opilione

Ken Ramos · Post by **Ken Ramos** » Fri Jul 17, 2009 6:15 pm

So this is how it's done...

EOS 30D w/EF-S 60mm f/2.8 Macro USM, 430EX Speedlite ETTL PP: Photo Impact 6

Bruce Williams · Post by **Bruce Williams** » Sat Jul 18, 2009 3:49 pm

Nice capture Ken - both parties in sharp focus and interesting viewpoint too.

....pic1 looks like a couple of bagpipes mating

.

Bruce

rjlittlefield · Post by **rjlittlefield** » Sat Jul 18, 2009 4:07 pm

You know, I keep coming back to this, trying to make sense of it, and I can't. There's obviously something I don't know about the anatomy of these beasts.

What is that light tan thing between the two of them??

--Rik

Ken Ramos · Post by **Ken Ramos** » Sat Jul 18, 2009 6:01 pm

Bruce wrote:

....pic1 looks like a couple of bagpipes mating .

Well, how else would we get new bagpipes?

Thanks Bruce

Rik wrote:

What is that light tan thing between the two of them??

Penis

Opiliones, unlike spiders, have a penis, but it is in their mouths for mating, from what I have read. Oh, yuck!

I would only assume that the "tan thing," is sort of like a "boot," like what would be between a camper shell and the cab of a pick-up,

maybe to keep things a bit tidy in the process. But alas, I am only guessing at what it is but more than likely a reproductive organ or a part thereof.

Thanks Rik

beetleman · Post by **beetleman** » Mon Jul 20, 2009 9:02 am

Now this one should make it to the books Ken. I have never seen anything like this before. It looks like there are flaps on each subject, like the flaps on the undersides of crabs and the tan thing looks like it is coming out of the lower one. Excellent find Ken.

rjlittlefield · Post by **rjlittlefield** » Mon Jul 20, 2009 10:07 am

Ken Ramos wrote: Rik wrote:
What is that light tan thing between the two of them??
Penis Opiliones, unlike spiders, have a penis, but it is in their mouths for mating, from what I have read. Oh, yuck! I would only assume that the "tan thing," is sort of like a "boot," like what would be between a camper shell and the cab of a pick-up, maybe to keep things a bit tidy in the process. But alas, I am only guessing at what it is but more than likely a reproductive organ or a part thereof.

Thanks, Ken. I tracked down some more information on this.

From http://en.wikipedia.org/wiki/Harvestman_anatomy:

While the genital opening, the gonopore, derives from the second opisthosomal somite in all arachnids, it is displaced between the fourth pair of legs in harvestmen, thus appearing to be part of the prosoma. The ovipositor or penis is withdrawn into the first opisthosomal somite. The openings of the respiratory system, the spiracles or stigmata, are located on the sides of the second somite.
...
The basic structure of the reproductive tract is similar in both sexes, with a mesodermal gonoduct (sperm duct or oviduct) emerging from both sides of the U-shaped gonad (testis or ovary). The two gonoducts fuse into a single duct, which leads into a cuticle-lined duct derived from the ectoderm into the open through an organ (penis or ovipositor) that can be everted through a combination of muscles and hemolymph pressure. These eversible organs play an important role in determining taxonomic relationships.

The penis is often complex, consisting of a long shaft and a shorter glans at the end, which is often equipped with various projections such as spines. In many species muscles move the glans relative to the shaft, but in Grassatores these muscles are lacking, and the movement is achieved purely by hydraulic means. A muscular propulsive organ, which pushes the ejaculate out, is missing in Cyphophthalmi, which have very short penises.

Cutting through the technical jargon, I think what we're seeing in the picture is the male's organ, everted from just underneath that big flap on the underside of the individual on the right.

Very interesting. But Ken, I'm sorry to say that the part about "in their mouths" sounds like a porn flick legend. Too bad -- it is a memorable thought!

--Rik

Harold Gough · Post by **Harold Gough** » Mon Jul 20, 2009 11:08 am

The leaves frame the subjects nicely, such that a wider crop might be better.

Harold

Ken Ramos · Post by **Ken Ramos** » Mon Jul 20, 2009 11:59 am

Rik wrote:

I'm sorry to say that the part about "in their mouths" sounds like a porn flick legend.

Well, I think I may have read that on Wiki, not sure. If it is legend, such as them being the most poisonous of spiders thing, I am glad that it is on them and not us!

You know Doug, now that you mention it, it does remind one of the bottom of a tastey Chesapeak Blue. I think that I read somewhere, here I go again, that spiders and crustaceans, e.g. crabs, are related?

Thanks Rik, Doug, & Harold