Bug / mysterious insect in my tank??

[Mordecai13]

Is there anything I can be doing proactively other than just waiting to spot one?

[Tony s]

On 7/7/2024 at 11:45 PM, Mordecai13 said:

Is there anything I can be doing proactively other than just waiting to spot one?

Just wait and watch. They progressively grow larger from the egg. No real pupal stages. So once they hatch, they look the same until they molt and reveal their wings. When it’s small it’s not going to be a danger to fish. Maybe fish eggs, you can definitely see it when it’s big enough to think about your fish. 

[johnnyxxl]

If they are small enough your fish may eat them.

 

But they are hunters and can catch small fry.

[TOtrees]

FYI the first pic in the original post is a shed exoskeleton. Can't tell if it's from the same individual insect as the 2nd pic. 

[Guppysnail]

On 7/6/2024 at 9:54 PM, Rube_Goldfish said:

Do damselfly nymphs (

Yes they do. I get them every year. They will molt many times just like shrimp. They can live in the aquatic nymph state for a few months to 3 years. They grow and develop based on the amount of food that’s available.

Anything that will kill these will kill everything else in your tank long before it kills them. 
 

Manual removal. Pest snails are their main prey.  Nothing likes to work harder than needed for food.  Shrimp and fish fry are next. As they reach maturity they will go for things the size of very small nano fish.
 

Take a flashlight at night when it is dark. They come out at night and have bright eye shine when hit by s flashlight. Look in substrate. They burrow in the younger stages.
 

This applies to both dragonfly and damsels.  Though yours does look like s damsel.