What are these tubes on my tank, after all?

[Lanpenn]

Hello everyone, how is it going?

Well, despite not posting my aquarium's photos here anymore (lack of time and other priorities), my tank's doing well and the cyanobacteria are almost eliminated.

However, I realized that there are simply so many tubes around the aquarium! These tubes are on surfaces from the rocks and glass. Today, when I was taking photos, I saw a small worm "taking a look" outside of one of the tubes. It resembles slightly the bloodworms, but I never saw any pupae, so probably is not Diptera.

For 11 years, indeed, I never saw anything like this.

Unfortunately, I don't have a good microscope with an attached camera (a thing extremely expensive here in Brazil), if not I could try to find out what creatures are these inside these tubes.

Thanks for attention and Merry Christmas!

 

[Colin_T]

They look like bloodworms (Chironomid midge larvae). The larvae make tubes on hard surfaces and stay inside the tube. They put their head out to catch tiny bits of food passing by.

 

[Lanpenn]

That's interesting. Today I was looking and... I found one suspect of being an adult from one of these worms from these tubes...

These creatures seem to be from the subfamily Chironominae. They resemble this species.