Why has this damselfly held this pose

[Barbie6803]

I was photographing a Willow Emerald Damselfly when it suddenly kinked it rear end into a J shape. Why?

[wint]

If it was a male (and depending on which way the J goes!) then it could have been transferring sperm from it's primary genitalia to its secondary genitalia.

HTH, Paul

[Barbie6803]

The 'J' shape was downward

[Jason Green]

Sometimes they can be deformed as a result of pupal problems, though here if it changed in front of you then maybe there is only slight damage.

[Dogghound]

The abdomens are very flexible and they can be moved quite easily, despite them looking so rigid. Could it have been cleaning itself? or could it have a parasite? hard to say really from a photo without seeing the action.

[RoyW]

Originally Posted by wint

If it was a male (and depending on which way the J goes!) then it could have been transferring sperm from it's primary genitalia to its secondary genitalia.

HTH, Paul

Originally Posted by Dogghound

The abdomens are very flexible and they can be moved quite easily, despite them looking so rigid. Could it have been cleaning itself? or could it have a parasite? hard to say really from a photo without seeing the action.

As Paul will no doubt say if he posts again after seeing the photo, this isn't a male transferring sperm (though it is a male).
It also doesn't look like it is cleaning its self (cleaning involves body parts being rubbed together; the abdomen being rubbed against the wings to clean the wings, and the abdomen being bent forward under the body and dragged through the legs to clean the abdomen), I can't see how this 'body shape' would help in anyway. I can't see any visible parasites, but as Dogghound says its hard to say what's going on without seeing the action.

Originally Posted by Jason Green

Sometimes they can be deformed as a result of pupal problems, though here if it changed in front of you then maybe there is only slight damage.

Usually a damselly with an abdomen shaped like this would be one which had hit an obstruction while expanding the abdomen during emergence causing it to twist, this results in a permanent deformation with the abdomen harding in the wrong shape though - clearly not the case here if it straightened itself out.
Edit: I meant to say - there is no pupal stage in dragonflies Jason (I'd expect someone with your knowledge of invertebrates to know that, although I realise that Odonata aren't one of your favoured subjects!;D).



Although I'm only speculating, I would suggest that something like muscle cramp might be an explanation. I see no reason why other animals, even insects, shouldn't experience something similar to the muscle cramps that we get - and I know that when I have had cramp in my hand before, my fingers can end up twisted into strange positions!

[Jason Green]

'Scientific-typo ()', I meant well, you know, whatever the stage is between water-dwelling larva and fully-fledged adult - the developmental-period in between. Concede on cause though, of course!

EDIT: Final moult.

You're correct though of course, these aren't really a group I've had my head turned by and so my knowledge here is zilch...

[Barbie6803]

Thanks for all your suggestions, not sure any of them are correct though. The damselfly didn't look at all distressed and carried on resting afterwards, allowing me to take a whole host of shots. It did flit off from time to time but returned within seconds to the same piece of dead cow parsley.

[RoyW]

Originally Posted by Barbie6803

Thanks for all your suggestions, not sure any of them are correct though. The damselfly didn't look at all distressed and carried on resting afterwards, allowing me to take a whole host of shots. It did flit off from time to time but returned within seconds to the same piece of dead cow parsley.

The truth is that you aren't going to get an explanation from this single photo and your brief description - and I very much doubt that it could be explained even if you had filmed the behaviour in high definition and could slow it down to watch frame by frame. It's not typical sperm transfer or cleaning behaviour, but other that that all that can be said is that it was flexing its abdomen for some reason (anything else is speculation).
If something did cause some sort of pain, which then caused it to flex its abdomen like this, the movement of the abdomen would probably be the only indication of distress that you would see - and if the pain passed it would then be expected to carry on as normal.

Originally Posted by Jason Green

'Scientific-typo ()'

I knew that would be the reason!