Pincushion urchin size

[Seadoc]

Hi all,
For those who have pincushion urchins (Lytechinus variegatus), how big have they gotten in your systems and how long did it take to get there? The website states they can get up to 8", which will be too big for my reefer 350 (81g DT), but I have seen them in DTs way smaller than the one I have.

 

[AcroNem]

They do get large. Takes a long time though. Of the 6 permanent pincushions I have, 3 are on the small side about an inch and a half and have only grown a little bit in a couple years with no supplemental feeding. The others were a bit bigger when I got them and I feed nori twice weekly, these grew quickly and now look like this.

They are fairly long lived and will grow slowly if you get small ones and allow them to graze so long as they won't starve.

 

[Seadoc]

They do get large. Takes a long time though. Of the 6 permanent pincushions I have, 3 are on the small side about an inch and a half and have only grown a little bit in a couple years with no supplemental feeding. The others were a bit bigger when I got them and I feed nori twice weekly, these grew quickly and now look like this.

They are fairly long lived and will grow slowly if you get small ones and allow them to graze so long as they won't starve.

Thanks!! I read some concerns regarding urchins eating the silicone glue from the glass panels. Any concerns about that?

 

[Neoalchemist]

Thanks!! I read some concerns regarding urchins eating the silicone glue from the glass panels. Any concerns about that?

Certain urchins do, but I dont believe the species you have are known for it.
In general though, I find that if there's only one urchin and no fish to bother it (many fish snack on urchins soft tentacle arms) then they will grow fast. If you keep more than one the competition will slow them down.
If they have plenty of rubble to protect themselves they will also work much faster.

 

[AcroNem]

Thanks!! I read some concerns regarding urchins eating the silicone glue from the glass panels. Any concerns about that?

Any urchin I've kept has never eaten silicone off a tank. I suppose it's possible though

 

[Seadoc]

Thank you!!!

 

[mfinn]

They do get large. Takes a long time though. Of the 6 permanent pincushions I have, 3 are on the small side about an inch and a half and have only grown a little bit in a couple years with no supplemental feeding. The others were a bit bigger when I got them and I feed nori twice weekly, these grew quickly and now look like this.
They are fairly long lived and will grow slowly if you get small ones and allow them to graze so long as they won't starve.

Are the pincushions the desired urchin for algae removal?

 

[AcroNem]

Are the pincushions the desired urchin for algae removal?

I use them most. They will carry stuff around though. Rock urchins are good too. Pencils and longspine I will not put in reefs.

 

[mfinn]

I use them most. They will carry stuff around though. Rock urchins are good too. Pencils and longspine I will not put in reefs.

Thanks