As always, an indication of the size (length) of the specimen would be helpful. The insect in the photo (on the basis of the shape of head and abdomen, antennae, ecc.) reminds a juvenile stage, maybe the first instar, of a dragonfly (Odonata Anisoptera). I believe that this is the right identification. Regards,

Rinaldo Nicoli

Sir, thanks a lot for your kind help. I checked some photos of juvenile of Odonata and find close resemble with what I found in lab. Thanks again for your clear explanation.

Regards,

Nazia Hossain

Yes it may be nymph stage of odonate but always mention the size  this helps taxonomists it cant swim but will be moving on the bottom surface or walls of water container they are good biological control for mosquitoes larvae as well

Sir, unfortunately the size wasn't measure that time. But approximately it'd range from 2mm-3mm and the pictures and videos was taken under 40* magnification. And, yea, the water collected from bottom surface.

Thanks a lot sir for your detailed information. It'll help me a lot.

No doubt .... it is  the nymphal stage of Dragon fly. Find out another one and check it developmental biology.

A confirmation of identification may also be obtained by examination of specimen head ventrally: the juvenile stages of Odonata have a special and exclusive type of mouthparts, i.e. chewing prehensile mouthparts. In resting position, the so called labial mask, very characteristic and belonging to this type of mouthparts, covers the ventral surface of the head.

An observation as regards swimming in juvenile Odonata: in damselflies (Zygoptera), they swim by fish-like undulations, as the long abdomen and the gills function like a tail. In dragonflies (Anisoptera, at least in some families), they can forcibly expel through the anus, like jet-propelling, the water introduced in their rectum for breathing purposes (they have internal, rectal gills), for very rapid movements in the water.

Regards,

Rinaldo Nicoli

ok .....great information sir,,,, thank you very much....

nymphal stage of Anisoptera (Odonata). A better pic from antennae should be help for say anymore

Dear Santhos Sir,

Thanks a lot , for your kind advice.

Will try to do so.

Dear Rinaldo Sir,

Thanks a lot for such detailed information. It's going to help me a lot in my study.

Now the concept is cleared to me.

Regards,

Nazia 

Dear Oscar Sir,

Sorry but I don't have any other view of the organism right now. Will try to collect and observe as u directed.

And thanks a lot for your kind help.

you are welcome

Dear Nazia,

May be a spider

dear nazia...

it may be lice or mite

Dragonfly larva, similar to Sympetrum (Libellulidae)

Dear Nazia:

With a photograph of poor quality, the only thing you can do is generate more confusion and sterile discussions that do not reach any reliable identification. It is best to repeat the photo with a higher resolution camera.

Regards,

Luis Miguel

Dear Dewanand Makhan Sir,

it's may not be a spider, as having 3 pairs of leg like insect.

It's may be a larvae of dragonfly as mentioned by others. Though I'm not that much sure and thanks for your cooperation. 

Dear Abbas Hamza,

Thanks for your kind help. I'll checked it out.

Dear Sarah Alexandra Corbet Mam, 

Thanks a lot for your help. I also think it's a larvae of dragonfly, as it has close resemblance when I checked other photos of Odonata larvae.