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Determine B jacksoni maturity

Discussion in 'Scorpions' started by elportoed, Sep 25, 2009.

  1. elportoed

    elportoed Arachnobaron Old Timer

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    I have a few B jacksonis for a while, starting with 5, but 2 died mysteriously along the way.

    I'm not sure which instar they are. They recently molted. One of them is showing the male traits, bulbous pedipalps. Is that the sign of maturity? He's around 2 inches measured from head to tail (not stretched, I'm not gonna make him do that).

    Is it safe at this point to put them together? I have them in separate containers.

    Another question too is how to determine the size. Some literature said males are 2-3 inches, and females are 3-4 inches. How is that measured (head to stretched tail, etc)?
     
  2. Michiel

    Michiel Arachnoking Old Timer

    How can we answer your questions, if we cannot see the specimens?
    If you post pics, we can tell, without pics, we can't. I don't know what "literature"you have been reading,but there is no such thing as a 4 inch B.jacksoni, male or female. Their max size is around 85 mm, but I never seen a specimen that large.

    Specimens around 2inches could be adult, and if there are specimens that have significant larger chela, these would be the males and yes they are adult then. Males mature at instar 5 and females at 5 or 6.

    Scorpions are measured from the edge of the carapace to the tip of the aculeus.
     
  3. If you see bulbous pedipalps, it's a mature male.

    If you have one the same size as a mature male but without bulbous pedipalps, it's a subadult female. As mentioned, females go through one more molt. The difference between subadult and adult in females is quite substantial, especially in the size of the metasoma.

    Adult male, subadult female:
    [​IMG]

    Adult male, adult female:
    [​IMG]

    Recently matured female compared to exuvium:
    [​IMG]
     
  4. elportoed

    elportoed Arachnobaron Old Timer

    I was trying to take a picture of him this morning to post here. The good news is he is a male, the bad news is that he died. I was going to nudge him to move on a cork piece so I can take his pic but he didn't want to move. I thought he was playing dead, but he is really dead. I lost 3 already without good reason. It's pretty frustrating.
     
  5. Don't beat yourself up. I started with five juveniles.

    One male made it to maturity, one female made it to maturity. The male died two weeks after the female matured. Then she died about eight months later.

    One subadult female died for reasons unknown, and one appeared to have bad mycosis.

    One juvenile female, the runt, had a bad molt and died getting out.
     
  6. elportoed

    elportoed Arachnobaron Old Timer

    It's very discouraging. If I know what caused the death, at least I can be at peace with it, avoid repeating the mistake. Not knowing the cause is killing me. I'd like to get a few more, but this kinda put a brake on things. I still have 2 more left, and they both could be females.
     
  7. elportoed

    elportoed Arachnobaron Old Timer

    This sucks!!

    One of the last remaining two B jacksonis molted out male. He died a couple of weeks after molt. I have no clue why.

    4 down, one more to go.
     
  8. Michiel

    Michiel Arachnoking Old Timer

    Well, if one dies it could be coincidence, but if more die, it is possible your are not keeping them the right way. They didn't die from old age......
    Keep them between 22-25 Celsius and 70-75% RH (which translates to a nice weekly misting) and on humus/cocopeat......

    Ps. You wouldn't be keeping it in a (damn those things) KK (kritter Keeper), aren't you? If so, change the enclosure, KK's are only suitable for desert species.
     
  9. Selket

    Selket Arachnobaron

    Why is that? Poor Ventilation, which means stagnate air?
     
  10. Michiel

    Michiel Arachnoking Old Timer

    The opposite. In a Critter Keeper the ventilation is so well (lid), that you cannot maintain 70-75% RH.
     
  11. elportoed

    elportoed Arachnobaron Old Timer

    I keep them in deli cups with few holes drilled on the lids, so they aren't that well ventilated. The substrate is peat, I keep it moist on one side. There's a corkbark for them to hang on or hide in. The temp may be as high as 90s and as low as high 60s at night.
     
  12. Selket

    Selket Arachnobaron


    That is odd, I just moved my b jacksonis from deli cup type things with holes in the lid and a few in the side of the container, to small kritter keepers, and the substrate stays more moist longer than when I had them in the deli cups. I am actually starting to worry about mold in the kk.

    Mine are thriving though. I rehoused them since they pretty much outgrew the deli cups, they couldn't really hang on the bark in the delicup. Now they are in a small maybe .5 gallon to 1 gallon kritter keeper.
     
  13. I have never had a problem keeping forest-dwelling species in Kritter Keepers; in fact, I had four U. mordax have successful broods this year and three of them were in KKs.
     
  14. Michiel

    Michiel Arachnoking Old Timer

    that's indeed odd, but if it works for you, who cares if it's odd :D
     
  15. Selket

    Selket Arachnobaron

    1. I know I am resurrecting this thread.

    2. So does this mean that females molt 1 more time than males, or once females molt into instar 5, they are mature and won't molt again.

    I have been looking and trying to find out to breed my b jacksoni, but haven't found much. For some reason I was thinking that females molt one more time than males, I don't know where I heard this, but I think I have always thought this.

    Thanks
     
  16. Michiel

    Michiel Arachnoking Old Timer

    That means that in some occaisions a female turn mature at instar 5 and others in instar 6. In my experience, most of them turn adult in instar 6.

    It is not uncommon in some buthid genera, that females molt one more time, than males.

    Cheers, Michiel
     
  17. Selket

    Selket Arachnobaron

    Is there anyway to tell if they are mature? Or should I just stick them together and hope for the best. Everyone is 5th instar.
     
  18. I would just wait for the females to molt once more to 6I.