Should I be worried about this ET look-a-like bug?

[Rupert]

For several days family members have mentioned about a strange looking spider in my tank. Well tonight there were two and I removed both of them!

Should I be worried about this ET look-a-like bug?
Does anyone know what it is?

[vinz]

Don't recognise that, but try searching the web for aquatic insects.

Any missing fishes? Some aquatic insects are piescivorious. Other than that, I wouldn't worry about an alien infestation taking over your household. Remove them whenever you see them. Try not to use hands in case they posess a nasty sting, at least until you identify them as harmless to humans.

They probably came in with the plants or wood... or maybe an adult insect flew in and laid eggs. Other forumers (including myself) have found dragonfly nymphs in their long established tanks.

You could keep them in a separate tank... could make an interesting science project for the kids (if you have any). Or bring to school for the bio teacher for extra brownie points.

[ranmasatome]

Looks like a damselfly nymph. looks pretty Juv now...see if it has external gills at the abdomen area..on the side usually or right at the back like tail feathers..
Dragonfly nymphs look almost similar they tend to be larger (sometimes) and have internal gills... if it doesn't have those gills then its probably a draggy nymph..... look for the retractable jaw..its REALLY cool when it eats smalls fishes and stuff like that..

I LOVE INSECTS..
Take some clearer pics of it in the water...

[Rupert]

Thanks Vinz & Ranmasatome

Thanks for the feedback, I am not sure what the two of them have been eating, no fish missing, but I did get 30 small cherry shrimp a few weeks back and can only ever count ten at one time… wonder how many of them have been eaten!

I searched on the web for Damselfly Nymph and came across a Dragon Fly nymph [Four-spotted Chaser] that fits perfectly. They have nasty eating habits, so I hopefully have exterminated the only two in my tank.

http://www.nature-diary.co.uk/2004-08-05.htm

[stormhawk]

Rupert, that's a dragonfly nymph of dunno-what-species. Each species's nymph has a different look but is similar in having a short body. Damselfly nymphs almost always have elongated bodies with two tail-like extensions at the ends.

Kill any that you find, if you don't want to lose any young fish. Or keep them separately and feed them with feeder fish or invertebrates like worms, that is, if you want to see the eventual metamorphosis. Its pretty interesting to see them undergo the transformation and their feeding habits can be fascinating for those who like to observe aquatic insects.

[ranmasatome]

Yeah..thats what i mean...those tail extensions are the external gills found only on damselfly nymphs..so if it doesn't have them then its probably a dragonfly nymph.
Anyway..i dont know if its the 4 spotted chaser...IDing insects gets really to the nitty gritty when you go to the species level...i've been doing flies myself for the last year...all i can say is WOW...headache but fun..

[loupgarou]

erm, how long take to metamorphize? read that dragonflies take like 5 years...

[ranmasatome]

i think that is dependant on the species..most temperate species will complete one life cycle in the course of a year..thats because water bodeis feeze over and places get cold.. in the tropics..where the temperature is more stable..they CAN take up to five years... so if you want to keep that guy..i reccomend that you ID it first...lol..you may be keeping it for a really long time..haha..

Anyway...if you want you can poke it in the water and see what happens...its quite cool when they use their abdomens as water jet propulsion systems to move away fast..

[Rupert]

The two that I had and hopefully that’s all, moved quite quickly and I had too net them. Why both of them came out in the open at the same time I am not sure, but pleased they did.

I also have lots of guppy fry and hopefully they have been eating them instead of the cherry shrimp.

[juggler]

Looks like a damselfly nymph. looks pretty Juv now...see if it has external gills at the abdomen area..on the side usually or right at the back like tail feathers..
Dragonfly nymphs look almost similar they tend to be larger (sometimes) and have internal gills... if it doesn't have those gills then its probably a draggy nymph..... look for the retractable jaw..its REALLY cool when it eats smalls fishes and stuff like that..

I LOVE INSECTS..
Take some clearer pics of it in the water...

Yes. I saw a documentary on this on Arts central some months back. It's really aweome when they can target a fish just by extending its lower jaw -- like a chameleon with a sticky tongue.

[Fei Miao]

Better get rid of them as soon as you can. Once I had to strip down my 20 gallon because of 2 of these fellas

[ranmasatome]

So bad ah?? must be keeping shrimp and small fish only right?..lol

[Rupert]

I haven’t seen any nymphs in a about two weeks, yesterday I did a large thinning of my bushiest plant [Wallichii] and captured my 5th nymph today! My guppy’s are so plentiful that it would be my luck that these are not getting eaten, rather my few visible Cherry shrimp [two with eggs] are. Anyway always scanning the tank now for any sight them, with a net handy to remove them at a moments notice.