Sexing my Damon medius whip spiders

[Sikalisko]

I finally got around to sex my D. medius whip spiders. I bought 7 of them from UK around two and a half months ago so I figured they should be well enough recovered from the shipping stress by now.

Hopefully some amblypygid pro can confirm my results, and maybe comment whether I should suspect my specimens being some other species than medius. I can tell that they are from west-African group and not D. johnstonii. D. johstonii should be the only other Damon species found in Nigeria and D. medius the only species found in Ghana.

I determined the sexes purely on the presence or absence of reddish hair on the posterior margin of the genital operculum. As you can clearly see from specimens 1 and 3, the "elbow method" used for D. diadema doesn't seem to apply at all. When I tried to gather information about this species outside scientific articles, this was mentioned multiple times as usable method for D. medius as well. Well, mostly on the youtube comments or instagram but still, people should stop being wrong in the internets already (that being said, I hope I got my information about this "hairy method" correct, it would be really embarrassing otherwise).

The first 3 were photographed trough a plastic container, before I uploaded the pictures on PC. I noticed the plastic wasn't clear enough and decided to photograph the rest in more difficult way on top of a sheet of glass. Sorry about that.

Numbers 1-5 are from Nigerian population and 6 and 7 from Ghana. This post is going to be a bit picture heavy but hopefully they serve as a comparison material for others who become new happy owners of D. medius as well.

Specimen number 1: Female



Specimen number 2: Male, also note the parasite hanging from underneath the ventral sac cover. It seems to be a good idea to inspect your wild caught individuals even if you aren't planning on breeding them and don't care about what sex they are. Chances are my acquaintance is going to be really excited about this finding even though I or my pet aren't that thrilled about this extra friend that just doesn't seem to get enough of my whip spider's company.



Specimen number 3: Female



Specimen number 4: Male



Specimen number 5: Male



Continuing with the Ghana specimens..

Specimen number 6: Female



Specimen number 7: Male

 

[schmiggle]

also note the parasite hanging from underneath the ventral sac cover

Dark brown, paired white stripes? Wanna make sure I'm looking at the right thing.

 

[Sikalisko]

Dark brown, paired white stripes? Wanna make sure I'm looking at the right thing.

Seems you got it right. Sorry the pic isn't super clear so you can't see the details well. I made quick and dirty cropped photo with arrow pointing on the parasite. Since it's easier than trying to explain anything.

I believe it might be some kind of Strepsiptera sp. but I really don't know anything about parasites, especially those that live in or on arthropods. I will probably make separate thread about it if my acquaintance/colleague who's more knowledgeable of parasitic insects can figure out what it actually is, and hopefully knows some good techniques how to take it off without harming the whip spider.

 

[schmiggle]

Seems you got it right

Lol nope. Thanks for pointing it out. Strepsiptera seems reasonable, but you'd probably have to pull it out to really know

 

[Sikalisko]

Lol nope. Thanks for pointing it out. Strepsiptera seems reasonable, but you'd probably have to pull it out to really know

I guess posting pictures is always the easiest way to make sure you get understood, as long as it's possible. At least I'm horribly bad at describing something like this

Yeah, it has to be pulled out somehow to see what taxon it actually belongs to but hopefully this biologist I've mentioned knows whether you can just simply pull it out or if it has some kinds of hooks to attach itself and it needs to be anesthetized first. Anyways, I'll probably have to bring my pet into some lab so that the parasite can be preserved right away. Since this parasite could also be from Nigeria, chances are it's non-described species and it's wanted as a sample

 

[schmiggle]

Since this parasite could also be from Nigeria, chances are it's non-described species and it's wanted as a sample

Yes, I imagine so. Parasites of amblypygi have received very little attention in the literature, at least as far as I could find.

I'll be following this story closely.