Hundreds of small white slug (with legs) like critters

[firstsalttank91011]

Hello all!

I have hundreds of small white almost slug like critters I'm having a terrible time trying to identify online looking for some guidance on. They only come out at night and cover the rocks and walls covered with coralline algae (not on the clear glass).

All the usual follow up questions. Are they bad for the tank? if so, good ways to get rid of them? etc.

Tank info
120 gallon display ~10 gallon sump with refugium
78-80 degrees
1.025 salinity
Slightly elevated nitrate and phosphate
All other parameters usually in spec
12 fish (mostly smaller with a medium size blue hippo and sailfin tang)
~2 years old tank
10-20% water changes per week (though lately it's been a bit more due to a malfunctioning protein skimmer)

As always, thank you for the help!

 

[Mr_Knightley]

Those look like chitons to me, relatives to slugs and snails with a segmented shell. Fantastic CUC if that's the case, but a picture from underneath would be needed for a 100% ID.

 

[EricR]

Those look like chitons to me, relatives to slugs and snails with a segmented shell. Fantastic CUC if that's the case, but a picture from underneath would be needed for a 100% ID.

Agree,,, chiton,,, good.

Lots of posts on here with similar -- here's just one example:

Chitons

 

[firstsalttank91011]

Awesome and thank you so much for the ridiculously fast replies!!! I will do my best to get a picture from underneath. I started doing some research on chitons and did read there could be some that are potentially predatory, curious if there's anyway to identify that?

 

[EricR]

Awesome and thank you so much for the ridiculously fast replies!!! I will do my best to get a picture from underneath. I started doing some research on chitons and did read there could be some that are potentially predatory, curious if there's anyway to identify that?

I've never heard of predatory chiton being an issue in a reef tank but haven't been at this as long as many others on this site.

We should do an experiment in a contained environment:
clam/mussel on one side, nori on the other, chitons in the middle,,, see what they go after.

Just kidding,,, too lazy.
Happy researching...

 

[Brit’s Fish]

Lucky you! Chitons are good guys!