What could this moving substrate granule actually be?

TedsReef · Dec 17, 2018

Hello all. I've been seeing pieces of what I thought was substrate on my glass. I put a flashlight on it and it started to run towards the substrate... They 0.5-1.5mm (too small for my camera to pick up) in size and somewhat shaped like a dull arrow head. I can't see any type of legs on them. I tried searching but, without knowing where to start, I didn't have much luck. Any help would be much appreciated!

Coralreefer1 · Dec 17, 2018

Hard to tell without a picture! Some kind of a pod possibly...

Retro Reefer · Dec 17, 2018

Of course they will be impossible to ID without pic, could be limpets

Frtdrmrose7 · Dec 18, 2018

TedsReef said:
Hello all. I've been seeing pieces of what I thought was substrate on my glass. I put a flashlight on it and it started to run towards the substrate... They 0.5-1.5mm (too small for my camera to pick up) in size and somewhat shaped like a dull arrow head. I can't see any type of legs on them. I tried searching but, without knowing where to start, I didn't have much luck. Any help would be much appreciated!

Here is a limpet I found in my tank. Very small, you can see the specs of sand to use in reference for size. This one is upside down after I popped him off a hermit crabs shell. Is this similar?

TedsReef · Dec 18, 2018

Frtdrmrose7 said:
Here is a limpet I found in my tank. Very small, you can see the specs of sand to use in reference for size. This one is upside down after I popped him off a hermit crabs shell. Is this similar?

Thanks for taking the time to take this pic! It’s literally the size of one of the granules next to the limpet in your picture. Maybe it’s a baby limpet. It was on the glass and my camera wouldn’t focus on it so that’s why I don’t have a picture. I tried to catch it but no luck.

Muttley000 · Dec 18, 2018

Sounds like a copepod.

User · Dec 18, 2018

Arrowhead shape makes me think flatworm.

This guy started off about 1.5mm and moved away from light. Next time I saw him 3 weeks later he was 6 mm. I caught him and got rid

Some species are more ‘arrow-heady’ than others (not my pic)

reef lover · Dec 18, 2018

Acoel flatworms...harmless

TedsReef · Dec 18, 2018

neilp2006 said:
Arrowhead shape makes me think flatworm.

This guy started off about 1.5mm and moved away from light. Next time I saw him 3 weeks later he was 6 mm. I caught him and got rid

Some species are more ‘arrow-heady’ than others (not my pic)

Thanks. I'll keep an eye on them and post more pictures as they get bigger. I've been trying to find pictures of fan and tube worms at the stages of life before they become stationary for comparison as well.