Very tiny yellow slugs

chimbo84 · Dec 30, 2020

I have these things all over the back wall of my Evo 13.5. They seem to be eating the algae and leave tiny little trails. They don’t seem to be in my LR or corals either but there are quite a few now.
The image is zoomed in quite a bit. They’re maybe .5mm long and move around like a slug. Compared to images of flatworms, I don’t think that’s what they are. Any ideas?

KJ · Dec 30, 2020

Hard to ID from the pic!

chimbo84 · Dec 30, 2020

KJ said:
Hard to ID from the pic!

I can’t really zoom in anymore. That pic was taken with a 30x magnifying glass and my iPhone. I zoomed in and cropped that image as well. They’re really quite small but they look like mini banana slugs. I’ll see if I can get a pic with a handheld magnifying glass.

chimbo84 · Dec 30, 2020

After 45 minutes of trying to collect one and chasing it around with a handheld microscope, I finally got this pic with my phone. They’re fast at 60x magnification!

Anyway, I hope this helps in IDing these things.

samnaz · Dec 30, 2020

Very interesting. I have not seen something like this before... following.

lba4590 · Dec 30, 2020

I have these too! Millions in my sump, actually in all my tanks, even my QT tank and survived copper... no idea what they are but I don’t think they’re harmful at all.

chimbo84 · Dec 31, 2020

lba4590 said:
I have these too! Millions in my sump, actually in all my tanks, even my QT tank and survived copper... no idea what they are but I don’t think they’re harmful at all.

I agree. I don’t think they’re harmful and in fact appear to be eating nuisance algae. My blue damsel seems to be picking them off but not in significant numbers. I noticed the first one about a week ago and now I think there are a few hundred of them.