Looks like the damselfly nymph stage. My Dad & I build an outdoor pond when I was 13 or so... I use to find these and dragonfly nymph in the muck when cleaning. Weirded me out until I discovered what they were. This link shows pics that look very much like what you posted.
Dragonfly nymph have two long, hair like protrusions on their tail and damselfly nymph has three of those. They will eat what they can catch. I just caught them and put them in my outdoor pond. The adults eat a lot of bad insects like mosquitoes. They may eat your shrimp babies but not adults unless the adults are small. Look around the plants and under leaves and you will probably find more. I found 12 in my tank this spring. Fish will eat them.
Just thought I'd add that they can bite pretty hard too! I pulled out some forget-me-not from the pond and found one hanging from the skin in between my thumb and finger
I bought a really disgusting 10 gallon tank a couple months ago (freaking awful), and it had a bunch of these living in the gravel (it was nasty) with two nerites and a bunch of balloon mollies.
After a little bit of research I determined that they were Damselfly nymphs, yours look the same thing. They are hateful creatures, but it would be interesting to have one or a few in a small reperium with feeder livebearers or something.
UPDATE
One of my peacock gudgeons is missing....the smallest one.Do these things kill fish also?
I \ve looked in the tank but couldn t manage to see any nymphs....apparently they are either green ,either brown...Just like the plants and my substrate\ohko stones ,which have plenty of holes ,lots of hiding places.
After finding and id ing the creature ,I understood why most of my blue pearl shrimp were missing ,and some of the red ones too....and now a fish......
Should I tear the entire tank apart and restart from scratch? I'm one step away from tossing everything out the window......
How ironic... I actively seek these guys out when collecting live food for my aquarium, the darters and sunfishes love them. I can't see them taking out things the size of balloon mollies though... maybe young guppies at the most. Otherwise they'd just cling to whatever fish they catch! What you have is a damselfly nymph, as dragonfly nymphs tend to have a fatter shape. Don't go picking them up with your bare hands!
Actually it is a myth that they eat fish. The ones in the US can only eat things smaller than themselves. They are afraid of fish and will hide from them. Fish eat them. That is why they hatch in small ponds and slow moving water. Less chance of a fish eating them. Their usual diet is mosquito larvae, small water bugs, small tadpoles, and shrimp. Usually fairy shrimp. Check your plant stems. They will flatten themselves against the plant to camouflage their long bodies. They also like the underside of leaves. I would look for another cause for the fish deaths. It may have killed the shrimp but not a fish bigger than itself.
The missing fish wasn't even an inch long.....The thing is I don't see any remains....the shrimp or those damn things must have consumed it overnight....this is weird...
They aren't poisonous, they supposedly have a strange bite due to their retractable jaw. I don't think it's anything worth getting upset about, as they are interesting creatures to watch underwater and colorful, helpful predators of mosquitos once they emerge into the terrestrial world. They have a funny way of swimming too, if you happen to dislodge one from a resting spot. I've never had any issues with them anyways. I can confirm that they will take small fish flakes from time to time if one happens to flutter by.
EDIT: I forgot to mention, they will indeed emerge after some time - my little sister had one emerge from her betta tank. A beautiful blue one. They can be hard to catch though!
Yes I watched the video. That was a newly hatched fry of a small fish species that was eaten. Damsel and Dragonfly larvae are opportunist. However, large fry, larger than a shrimp or tadpole, or an adult fish is not at risk. Anything bigger than a minnow can eat them. I also do not believe the creature in the photo was of a species common to the US. There are extremely huge dragonflies in some areas of the world. The ones in the US are just not that large because of our short seasons. They have to mature in a few weeks because of weather and other environmental things. There are a lot of post this year from people finding these in their tanks. Including me. I have never hear any of the poster say their fish were eaten. Just their shrimp. Poor shrimp get eaten by everything.
Damselfly and dragonfly larvae are ambush predators likely to lurk among foliage waiting for munchies to wander in reach, when cabomba are lifted from a pond.
Such a gangly small larvae is likely to be snagged among the very long delicate and pretty foliage and hitch hike
When examining plants in water with a flashlight after dark, these can be easier to spot in water and some scissors used to snip them, additional munchies for other fish
Useful to know if where you have an isolation tub where you want to hatch eggs and need to eliminate such predators, bump off any you see after dark
Regards, andy
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
The Planted Tank Forum
3.5M posts
130.6K members
Since 2002
A forum community dedicated to Aquatic tank owners and enthusiasts. Come join the discussion about flora, fauna, health, housing, filters, care, classifieds, and more!