Pincushion urchin question

[Blndbunny]

i have a beautiful purple pincushion urchin in my sps zeo tank. She is super active, all over the tank, and has quite the collection of snail shells and rubble she carries around. I'm likely over thinking things here, but I'm worried. She has lost one spine. I know it's just one, I'm just trying to figure if this is a bigger issues. She is actively feeding on film algeas in the tank, there are spots of other algea (3 month olds tank) that she ignores. I have not added sheet algea to the tank for her, but I will if we think food is the issue.

Water, ammonia, nitrites, and nitrates are all 0, daily ph ranges from 8.01-8.2 through the corse of the day. Salinity is 35ppm. I haven't checked calcium, alk, or phosphate in a few weeks

Any ideas, or am I just being an over concerned tank owner? Thanks guys

 

[Snelly40]

if it's just 1 i feel like you are ok... it can happen... but keep an eye on him, if many start to fall out somehting could be going on... for now i'd say you're in the clear

 

[Blndbunny]

Ok. I figured that was likely the case, and my long spine is just fine and growing like a weed. It hitchhiked in the size of dime, and is now larger then a golf ball.

I have a lot of travel over the next month so I'm just trying to be very aware and catch any potential issues

 

[Oxylebius]

I used to keep tanks full of urchins in a laboratory - they eat a LOT. I would suggest supplementing its diet with algae. They can starve for months before showing any signs, then in 24-48 hrs drop all spines and pass away.

 

[Blndbunny]

Ok I will pick up some algea and start adding it

 

[Blndbunny]

@Oxylebius, how much should I expect them to eat, I have two in the tank. The purple pin cushion is a good 2.5" in diameter including the spines, and the long spine is a bit bigger then a golf ball counting his spines. He actually hitch hiked in and back in January his body and spines was about the size of a dime, cutest little thing ever, but he's growing like a weed. I just want to be sure to offer them enough. I am considering re-homing the long spine though because I know my system isn't big enough for the two.

 

[Oxylebius]

The long spins is a great grazer of lots of different algae. I had a tuxedo that was more selective, unfortunately.

Is your tank a nuvo 16? Then re-homing is something to consider, but I'd first try to get it well fed and healthy before moving it out. This will help it survive a tank transfer.

They can live a good 6 months to a year w/o food starving to death. If you just got it in January and it has grown fast, it has probably found enough food to eat so far and may only now be starting to starve. So, hopefully you are catching this early.

Hungry urchins will eat almost anything, if no algae is around to eat they have been found to eat dead/dieing creatures like sea stars and jellyfish, eating each other or other urchins, or anything else they can get a hold of.

Each species is a little different in what they prefer to eat. You may have to try a couple of different types of algae (sheets and pellets) until you find something that it likes. If you have some algae strips, you can start feeding it them first. My tuxedo used to just carry the algae strips around on him, but it did like to eat algae pellets, but I usually placed the pellets right next to it, so that the urchin could get some before the fish devoured them. The urchins I had in the lab ate kelp we havested from the sea and homemade urchin food (you can find the recipe posted on the link below). You may want to consider feeding daily until it get healthier.

In addition, for urchins to regenerate spines not only do they need food, but they need Ca, Alk & Mg. Article here. You may want to consider monitoring your levels and make sure they stay on the high end, the urchin is going to want to pull from the water what it needs to build spines. Or instead on monitoring, either do water changes more often or up the amount of water changes. In addition, allow it to graze on coralline algae, by eating this algae in particular it can take in calcium carbonate into it digestive system. I hope this helps.

Good thread of another on the forum who's urchin was loosing spins: http://www.reefsanctuary.com/forum/index.php?threads/a-naked-urchin.92763

 

[Blndbunny]

They are both in my 40g cube, which is a zeovit tank, my calcium has been in the 420-440 range, my alk has been about 7 which is right for running zeo, and my Mg was within range I just don't remember the number.

I will pick up some diffrent algeas tomorrow. Right now I know that they are both continually grazing on the rock, I'll see tiny spots of algea dissapear, and the pin cushion loves to clean the glass. I can't say they are finding adequate food, but both have grown, the long spine quite significantly.

Thank you so much for the extra info I'm really quite fond of these guys

 

[Oxylebius]

Keep us posted on their health. I'm also quite fond of urchins.