Mysterious insect

[Elena82x]

Does anyone recognise what this little creature is in my tank? I’m assuming he’s hitched a ride with a plant… about 2cm long.

 

[MaloK]

It's a Damselfly Nymph.

 

[Elena82x]

It's a Damselfly Nymph.

Thank you

 

[jaylach]

Happy that it was identified but I curious as to if it could be harmful...

 

[TNG]

It eats fry and small fish, so shouldn't be in the tank.

 

[jaylach]

It eats fry and small fish, so shouldn't be in the tank.

In that case squish and turn it into fish food! I actually know nothing about these types of beasties. It is like I don't get using mosquito larva as fish food. What happens if they are not all eaten? Do you end up with a house full of mosquitoes?

 

[Colin_T]

In that case squish and turn it into fish food! I actually know nothing about these types of beasties. It is like I don't get using mosquito larva as fish food. What happens if they are not all eaten? Do you end up with a house full of mosquitoes?

I have never seen uneaten mozzie larvae in tanks with fish
Mozzie larvae take a few days to change from the typical wriggler stage into the pupae and then a couple more days before they hatch out into adult mosquitoes. Fish will normally eat them as soon as they see them and unless you have lots of floating plants covering the surface, there won't be anywhere for the mozzie larvae to hide and turn into adults.

 

[GaryE]

When I first started feeding with mosquito larvae, I once had half a dozen of them in the house. I didn't know and caught them right before they took wing. If you harvest regularly, you get what @Colin_T described - a feast the food doesn't survive. I may have had one or two take wing since then, after feeding live every second day all summer for many years. In my fishroom, the window fans don't run at night, and mosquitoes can get in when they're off. It isn't a buggy summer, so I haven't had to block that yet.

Dragonfly larvae? I like them and have let them grow in certain tanks. I keep small fish in general, and they can become as big as the fish, depending on the species. I've never had one eat an adult fish, but juveniles and fry, yes. I've let them grow out in over productive livebearer tanks for population control, and let them go once they take wing.

The only live food I've had go really wrong is when wingless fruit flies get wings, either through a wild one someone getting in, or through a mutation.

 

[MaloK]

Thinking that an insect nymph can become an apex predator in an enclosed environment like an aquarium is a little disturbing...

On the enclosed environment... But it happens.