Sexing Scolopendra dehaani

[nepenthes]

Hello all,

A drowning centipede

It has been a little bit since I have been very active on the Myriapods sub forum, but I hope I can contribute a little bit of knowledge to sexing Scolopendra centipedes. I volunteer at the OSU Insectary, and plan on breeding their 9 centipedes, Scolopendra dehaani. So far I have confirmed 5 females and 2 male centipedes.

To start I would like to confirm that I didn't notice any outward differences between sexes. I know this myth still gets around. All of these centipedes are from the same brood, and have been at the Insectary for most, if not all of their lives. There was slight variation in the size of the centipedes, but if anything the Males looked bigger than the Females (Could males develop faster?). So hopefully this helps bunk the myth that you can visually differentate most Scolopendra centipedes.

Any ways Here are some photos of the 9 S. dehaani centipedes reproductive organs being popped.

#1 Female

#2 ????? (I am guessing female what do you guys think?)

#3 Female

#4 Male (Note the two projections, those are the Gonopods I believe)

#5 ????? (I am guessing female what do you guys think?)

#7 Male

#8 Female

#9 Female

#10 Female

For Centipedes #1-#3 I drowned, the rest I gassed out of convenience. For drowning the centipedes, I made a hole small enough so that the centipedes couldn't get out (and conveniently the right size for gassing the centipedes), but water could get in. I submerged the deli container with the centipede in it and first left the centipede alone for 5 minutes. It didn't take long for the centipede to settle down, but I found that they still were able to grasp my fingers with their legs. So I pushed it back to 15 minutes under water. This gave me an ample amount of time to pop the centipedes, and put them back in the container when I was done. All in all the centipedes were immobilized for about 5 minutes using the drowning technique. They all came too and were active after I was done knocking them out.

Here is the container with a little bit of air trapped in still, I had to make sure to get as much of it out as possible.

Centipedes #4-#10 (Centipede #6 died a couple weeks ago), I gassed using CO2. They had a cylinder so it was easy to just stick the tube into the hole I had already made. I gassed the centipedes individually for around 1 min. Which once taking their limp body out of the container, gave me around 1 minute to work with them. More than enough time to snap a couple photos and put them back in the enclosure. I have attached a video of a centipede being gassed.

Here is an image of the centipede gas chamber. Pretty minimal.

Also here is a video of a centipede being gassed.

All and all I am very excited to know the sexes, and next time I go in I will be attempting to breed them. Ill see what I can do about recording the process and how they interact.

nepenthes

 

[Galapoheros]

It's kind of a revisit but still nice to see the info, it's very slow here at times, something like a refresher course because new people show up and old threads and post seem to almost get lost. I mostly look at this feature concerning the spinning organ, looks pretty much the same in other sps too.(hope you don't mind me using your pic, I will delete it if so)

 

[nepenthes]

You wouldnt happen to know the name of that organ would you? And its no problem using my photo.

 

[Galapoheros]

It's part of the spinning organ, don't know the sci name for it. You can go to Youtube, type in "centipede mating" and get an idea.

 

[zonbonzovi]

Nicely done, especially since this is the most commonly imported species, at least in the US. I forgot how clearly horseshoe shaped that spinning organ is(at least on dehaani). I can't remember the proper name for it either. Spuzzblaster seems appropriate Good luck with your project!

 

[Amoeba]

Bravo Neppo! Nothing makes my day better than pics of drowned, gassed, and molested bugs. :3

 

[Travis K]

Bravo Neppo! Nothing makes my day better than pics of drowned, gassed, and molested bugs. :3

I think that makes you a Pede`O

 

[Daniel3x7]

So if I am correct I should be looking for that "horseshoe" and the little pointy things on both sides of it? I just want to confirm.... I might try this in the future and I want to do it right

 

[nepenthes]

Yep, thats about what I got from every one else. I was only looking for the gonopods (the two projections), but the horseshoe shape, according to Galapoheros is what to look for and expect in most Scolopendra males.

 

[Galapoheros]

It doesn't always look like a horseshoe, more pointed with heros at least, takes some getting used to. If there is something sticking out there, it's a male ime. I had to look at a lot of pics I took before I started to snap to it. I haven't done a whole lot of it btw but enough to see that the more pics a person looks at, the easier it is, kind of like it getting easy to sex reptiles.

 

[Lurchenstien]

I've decided to attempt to determine the sex of my S. dehaani, I'll most likely go with the drowning method later today.

Random question, as temperature seems to make a difference to how lively the 'pedes are, would water temperature make a difference to how long the 'pede was put out and the recovery time?

 

[zonbonzovi]

Random question, as temperature seems to make a difference to how lively the 'pedes are, would water temperature make a difference to how long the 'pede was put out and the recovery time?

Without knowing much about the properties of diffusion I would say 'no'? I *think* temperature extremes would have to be significant to alter the rate of diffusion but my knowledge is primitive in that regard. Luke warm seems like a good approach. Ultimately, you will have more than enough time to work with sexing if the animal is fully unconscious(that sentence made me feel dirty). Recovery will depend on how quickly water dissipates from the spiracles/trachea.

 

[Lurchenstien]

Cool, well I'll go with that. I'm gonna find the 'pede in a short while, may as well post back when I have some results, or if I can get a decent picture.

 

[Lurchenstien]

Well, the pictures aren't great, I really ought to invest in a decent camera, but The 'pede has recovered and I didn't get bitten. What are peoples thoughts on the sex of this 'pede? After looking at the pictures in the OP and these three for a while, I'd say it looks more like the pictures of the females than those of the males. The pictures aside, I can't say I noticed anything like the spinning organ or the gonopods as per the pictures above.

 

[zonbonzovi]

A bit blurry but the overall structure says female

 

[Lurchenstien]

That's cool then. I've been meaning to get a decent camera for some time, but something more important seems to come along, perhaps the next thing to do so might end up being a male S. dehaani...

 

[Elytra and Antenna]

Hello all,
To start I would like to confirm that I didn't notice any outward differences between sexes. I know this myth still gets around.
nepenthes

A myth is something that is never true, not something that is not always true. Your explanation would be like trying to prove the Emperor scorpion's ability to sting is a myth by holding one and not getting stung, except that you did not offer weight (or any) measurements to back up your mythbusting attempt (it's like you didn't even hold the scorpion).

 

[Lurchenstien]

As the centipede in the previous picture I posted in this thread is the one on the right in this picture, and has been for 45 minutes or so, that'll be a confirmed male and female S. dehaani that I have. The male is the only one of the four new dehaani that I didn't sex, as he's injured. I noticed he was acting wierd when I touched his terminal legs to get him to move, it looked like what I've read up on centipedes mating, so I figured I'd put him and the female together and keep a close eye on them. They've been together for near on two hours now.





Edit:
The male has spun the web, left the sperm packet, and the female has picked it up. Both centipedes are now back in their enclosures.

 

[Staehilomyces]

What kind of water did you use? To elaborate, I would like to know if normal tap water is safe to use, or whether there needs to be any preparation, purification or such to make it safe to use. It's just I'm planning to start breeding Australian 'pedes such as Scolopendra morsitans, Ethmostigmus rubripes (especially) and essentially any other centipede I can get my hands on. Also, is there any specific time of the year when you should introduce potential breeding pairs together, or will any time suffice?

Great job on the information you have provided though, as I have finally found the answer to how one can keep a centipede still long enough to sex it.