What are these worm-like things?

So, I went scooping around a local wildlife sanctuary dam recently to try to get some Daphnia, but had no such luck. I did however, find a funny little egg sac attached to a piece of Parrot's feather, and decided to hang onto it to see what would happen. It was very small, and had the gel consistency of a string of frogs' eggs, with tiny little black eggs in it. I popped it into a small, heated tank that I have my brine shrimp culture standing in, and it seems like the eggs have hatched into I-have-no-clue-whats. The little things are way too small to take accurate pictures of (I can try, I guess), so I made some detailed drawings with explanations and scales (yay for my A in matric biology haha), and hopefully someone can identify them from there. I don't even know if they are worms or some larval insect.


So, any ideas? I tried feeding them to two of the baby axies last night and this afternoon and they seem to be a hit. Haven't tried with the larger babies because I just want to make sure that they don't have any ill effects first.

 

Its bloodworms, a chironomid midge larva(Chironomidae).

I am surprised about the egg sac being gel-like, but it does seem certain species lay it like that.

Good snacks for fish

Edit: Good job on the diagram! I enjoyed it and, with your permission, I would like to use it in future

 

Those look like some species of bloodworm to me...
I know that there are some species of bloodworm that makes little tubes like that but i don't know what their eggs look like... I will do a bit of reading and see what i can find for you...

 

@Mzungu - they look like bloodworm to me as well, but the casings seemed strange for bloodworm. It reminded me of caddis fly larvae (but those are much, much bigger, and build their casings out of whatever happens to stick to them). And you're welcome to use the diagram - I made it in about five/ten minutes lol
@BugMan - That's really interesting - I didn't know that. I thought all bloodworm were surface-dwelling. I'd be really interested to know what you might find on them.

 

Depend on which caddisfly it is. Also, the casings they make, or rather, the materials they use, are often specific to a family/genus, which helps identifying caddisflies. It is definitely bloodworms, they make similar tubes in the substrate(out of view). To ID to species level, you'll have to wait for the adult midge to come out most likely, and even then chances are great that one would only get to genus level, if that.

Thanks for the diagram, I often go and teach primary school kids 'stuff' about the natural world, it might come in useful

 

@Mzungu - Very interesting and informative, thank you

 

@ Zeiphex - You will also notice that they are evenly distributed. If you watch them for a while you will see that they have a "yard" around their "house", where they will feed. They tend to not go into their neighbour's territory. However they do go to areas where there are no other houses (like on the sides of the container) to feed as well. This is my interpretation of their behaviour.

 

@AquaS - this is true indeed! Like I wrote in the diagram, they can always be found near/partially in their little houses. They don't leave the area at all. What do these things actually eat?

 

hmmmm... not sure if the initial egg casing found is Chironomid. As far as I know they lay single eggs by using the miniscus of the water to actually pull the eggs out. It sounds like Caddis to me. However, caddis will have small little legs that will be noticeable on the thorax most of the time. If it is just worm like then it is not Caddis.

Chronomids simply wont be able to lay an egg sack that big! Most chironomids are not even the size of the egg sack found.

 

Do they have segmented bodies?