Sunday 22 March 2015

Tank Troubles and Moulting Nymph Skins!

Earlier in the week when I went to check the tanks I noticed that one of the Emperor Dragonfly nymphs had moulted and the complete skin was on the surface of the water. Knowing that this must have happened when I was at work I set about trying to find it. Unfortunately I did find it, but it was in the jaws of the big Emperor Dragonfly nymph which had obviously found it resting up. I hadn't been caught long and as much as I didn't want to watch it, I had never really seen this beast in action. It eat it from the abdomen end first and after eating half of it, let it go where remarkably the small Emperor nymph dragged itself away to safety. It didn't last long however and did not make it through the night. I have since seen the Emperor Dragonfly nymph hunting small nymphs and its certainly feeding well. Looking in the other tanks, I have also this week seen the Brown Hawker nymph catching small shrimps, the speed of the attack when close enough is too quick for the eye to see. The Broad bodied Chaser unlike the Hawkers sits patiently and when something gets close enough, suddenly launches its attack. Lastly the Large Red Damselfly was seen eating a small damselfly nymph and almost looks ready to emerge soon. I will keep and eye on them as hopefully the next few weeks may see the first ones starting to emerge. I remember last year that the abdomen went quite red in colour prior to emergence, something to look for. I decided today to have a quick session at Nethergong where the idea was to catch a few small prey items for the nymphs in the tank and pond. After returning I thought I would have a photography session with the 20mm Emperor Dragonfly skin that had been moulted in the week. Depending on the species, dragonflies can moult 10 -14 times during larval development and each time a complete skin is left. When moulted the labial mask and Labial palps are visible showing the business end of why they are such dangerous predators underwater. After setting the camera up I took a number of shots from different angles and was able to study the mask through a magnifying glass, yet more new information to learn. I could have probably done with a 100mm macro lens for more quality and detail but they didn't turn out too bad with the 150mm macro lens. I have also seen a few damselfly skins as well in the tank so this may give me the excuse for another session later in the week maybe, if time allows!

Emperor Dragonfly Nymph (side view) 

Emperor Dragonfly Nymph (top side) 

Emperor Dragonfly Nymph (side view) 

Emperor Dragonfly Nymph (side view) 

Emperor Dragonfly Nymph (underside) 

Emperor Dragonfly Nymph (underside) 

Emperor Dragonfly Nymph (underside)

6 comments:

  1. Oho, trouble, but it was beautiful, well done Marc.

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  2. Some terrific photography Marc well done.

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    1. Thanks Mike. Not long to go now. Really looking forward to this season and seeing whether the 7d improves on last years efforts.

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  3. Absolutely amazing!
    You are now definitely "diseased" but the dragon virus! LOL!
    You go deep in depth of the matter, it's really awesome and your observations are neat and precise,
    Sincere congratulations :)

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  4. Enjoyed your text and images. We noticed a lot of nymph on nymph predation in our tanks last year, but I started to give them the occasional feast of garden worms and that seems to waylay their desire to eat each other for a while - although we still get loads of posturing. There also seems to be a problem with cannibalism when there are too many nymphs in a tank at one time - hence we now have several tanks set up. As soon as our pond tadpoles are wriggling freely I will catch a few to put some into each tank - they act as tank cleaners and make the tanks more natural so that the dragons can hone their hunting skills. The frog survivors get released back into the pond at a certain stage in their development. When the dragons get to the final in-star nymph stage, I do tend to free them to the pond - but sometimes we get surprised! Best Wishes in your pursuits - wonderful area to observe. Regards from Helen :)

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    1. Many thanks for the info Helen. Iv'e certainly learnt a lot so far doing this. I have a few tanks with various species in as well. I'm hoping to photograph the Large Reds as they emerge. Its certainly very interesting following this winter project.

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