Sexing small spiders

[Jonathan6303]

I was wondering how some would go about sexing spiders whose max size is around an 1-1.5 inches. The genus that is on my mind is sphodros but I also think Cyclocosmia and Native American trapdoors which generally don’t get very large. @Arachnid Addicted whats your experience with this. I know you worked with some actinopus and there relatively small too.

 

[Biollantefan54]

The only way I can think of short of looking at mature animals would be looking at the molts just as you would a tarantula. You might need something like a jeweled loupe or something more magnified like a a stereo dissecting microscope though.

 

[Jonathan6303]

The only way I can think of short of looking at mature animals would be looking at the molts just as you would a tarantula. You might need something like a jeweled loupe or something more magnified like a a stereo dissecting microscope though.

That’s what I was thinking. It would be very difficult to handle the molt too

 

[Biollantefan54]

That’s what I was thinking. It would be very difficult to handle the molt too

What I have done for really tiny molts is maneuver it using two thumbtack or needles or toothpicks. Using a stereo dissecting microscope and some toothpicks probably wouldn’t be too hard I think.

 

[Nicole C G]

As someone who identifies jumping spiders, 1.5inches is humongous. I try to put them into a clear plastic bottle and photograph their pedipalps and epigynum. It’s pretty simple from there. Males have swollen palps, females have a visible epigynum.
Sub-adult male Naphrys pulex, swollen palps, but look more balloon-shaped than adults. (He is 2mm)

adult female Naphrys pulex, visible epigynum (I can’t remember her size, maybe around 4.5mm)

 

[Biollantefan54]

As someone who identifies jumping spiders, 1.5inches is humongous. I try to put them into a clear plastic bottle and photograph their pedipalps and epigynum. It’s pretty simple from there. Males have swollen palps, females have a visible epigynum. View attachment 417156
Sub-adult male Naphrys pulex, swollen palps, but look more balloon-shaped than adults. (He is 2mm)
View attachment 417157
adult female Naphrys pulex, visible epigynum (I can’t remember her size, maybe around 4.5mm)

I don’t think it’s as simple with mygals though, I don’t remember seeing subadult males with swollen palps like how I see it with true spiders. I agree with you though 1.5” is huge haha, I’m usually looking at parasitic wasps that are just a few millimeters!

 

[Nicole C G]

I don’t think it’s as simple with mygals though, I don’t remember seeing subadult males with swollen palps like how I see it with true spiders. I agree with you though 1.5” is huge haha, I’m usually looking at parasitic wasps that are just a few millimeters!

Sorry about that, I meant a that’s how you check specifically jumping spiders.

 

[Biollantefan54]

Sorry about that, I meant a that’s how you check specifically jumping spiders.

No don’t be sorry haha! That’s still useful, but I think the op was curious about trapdoors specifically. I think what you said applies to most true spiders though, regardless of size, so it’s a good thing to note!