Some sort of fungi, not necessarily good or bad.

Titanopsis roots look a bit different (although I'm sure you saw that when you pulled it out).

Those look like fresh new rootlets. They are very fragile, more than likely when you pulled out the plant the roots simply broke at the tips. It's virtually impossible to get a fully intact root system out in one piece.

Titanopsis roots grow quite deep, it will do very well in a deep pot. You can throw in some chunks of rock to reduce soil volume in a bigger/ deeper pit if you're worried about the amount of moisture in the newer pot.

I stand corrected. =)

Usually II'm never repotting these when the mix is wet, so I don't really see that!

I do find Titanopsis roots do grow to fill pots nicely though.

Before I pulled it out I really loosed up the soil and took it out starting at the bottom of the pot. It came out easily since the soil was completely dry. When it came out there weren't any new roots, I understand that they can be broken but I think it was a fungi like ewwmayo said. The roots also weren't long, they were a clump and shorter.

Those are roots.

I saw white balls on the surface near the pot edge, which is another reason why I said fungi. Any chance you can look at those? I suspected fruiting fungi there.

In dry soil, fine roots break off extremely easy. Agree with polypom & xero...they are roots of something:)

ewwmayo, it looked like bits of quartz sand to me but I don't know for sure.

Might not be Titanopsis roots. Could be weed roots but I think Tehya would've mentioned a weed was removed.

what an adorable little plant, and so much new growth! I just recently got one, it's quickly becoming my favorite succulent :) looks healthy, so I doubt it's fungus. i agree, they look like tiny feeder roots

Ewwmayo,

That was a bit of borax I'm embarrassed to say. I was trying to get rid of some bugs. I read mixed opinions and then after applying I decided it was best not to use this type of treatment just in case and removed all I could.

After doing research I believe they are fungal hyphae strings

my pilosocereus has had its roots that way for as long as i can remember. theres no harm. at some point i thought they could be that way because the plant needed more water so it made the fuzzy stuff to reach out? idek lol. but i can assure you my pilosocereus is very healthy and yours look that way too. i think roots are fine as long as they are not black and shrivelled.