A naked Urchin

[Basile]

I have a Black Hatpin Urchin ( Echinothrix diadema)

At the begining he was very nice and seemed happy but because of my rock sculptures that i made, with lots of caverns he quicly lost his spines they broke.

And he never grew them back. Now in bulding my sculpture i did use some foam that i know he eate. But that was 5 months ago if it had damaged him he should already be dead no?

So this week i've put him in my macroalgae growth tank, its actually a storage tank for excess macro and my pod farm as well , he should be like a kid in a candy store in there lots of fresh algaes, lol. Maybe thats what missing. we'll see. Because during all that time he kept going strong anyway.

Anybody have any suggestion as to why he wouldn't regrow his long spines.

I write big for my iphone friends

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[Oxylebius]

Yes, urchins can regrow spines, both broken off spines and spines lost from the test (the tubercles). For some urchins they can grow them back in several months, others take longer. Sometimes this takes a long time, over a year to regenerate. Sometimes they don't grow back at all. There are studies on growth rates if you want to look up scholarly journal articles on it. Probably with most things that regenerate, they need an energy source, lots of food to do so.

 

[Basile]

Yes, urchins can regrow spines, both broken off spines and spines lost from the test (the tubercles). For some urchins they can grow them back in several months, others take longer. Sometimes this takes a long time, over a year to regenerate. Sometimes they don't grow back at all. There are studies on growth rates if you want to look up scholarly journal articles on it. Probably with most things that regenerate, they need an energy source, lots of food to do so.

Ok well as a matter a fact i just transfered him into my pod farm where their's a huge , and abundance of macroalgaes to snack on, that should help. It was my impression he was a bit miserable and slower and well needed some TLC. I've put one of his cousin a tux in there with him, so to give a chance to my macro in my display lol while these 2 are in there at the buffet, gorging themseflves silly they'll leave the junior leaves to take roots in the main reef lol. thanks for your input man.

 

[Oxylebius]

I worked with urchins in a lab and in my experience once they start loosing spines it is hard for them to pull through, prepare yourself, you might end up loosing it. Hopefully, it will go for the abundance of food and pull through. Good luck.

 

[Basile]

I worked with urchins in a lab and in my experience once they start loosing spines it is hard for them to pull through, prepare yourself, you might end up loosing it. Hopefully, it will go for the abundance of food and pull through. Good luck.

Thanks, he's been like this for a few months now its just when i started this little tank that i thought maybe he'd benefit from lots of algaes to eat. So i've transfered him in there , he's still going. Hope he makes it , thanks.

The only time i saw the inside of one is when i ate one in Italy.....their's nothing in there to eat, just full of pebbles and sand, for $18 its high robbery, if it was rubbery like the squid it'd be something, but its full of nothing...... don't ever order that on the menu. Snobery at its best, LOL. rant over lol.

 

[StirCrayzy]

I agree it's generally a sign of dire circumstances . I don't think having the tux in there with him will help. There is a.chemical warfare I've read about between urchins being in close proximity to each other. They release toxins and I know twice myself have had a completely normal healthy urchin die within months after adding a new specimen. I haven't come across any other logical explanation, stable parameters, no predators, and not due to lack of food. Wish I could remember where I read that.

Oxy, have you come across info of that nature? What type of lab work did you do with them?

 

[Oxylebius]

I worked with the purple urchin (Strongylocentrotus purpuratus) in a developmental biology lab. Didn't mix species in tanks, had only the purps species in each tank and keep ~10-15 urchins per 10g tank. No issues with keeping the same species in a tank.

Haven't read anything about not keeping two different species of urchins together, but it is entirely possible that urchins of different species would release toxins to prevent a competitor urchin in their tank from eating their food, by killing them, urchins are full of toxins. Particularly in smaller tanks where toxins can build up. They consume LOTS of algae a day if they had the chance. Most people are probably not feeding their urchins enough. They can live a good 6 months to a year w/o food starving to death.

Would like to read that article on urchin toxins, if you happen to come across it.

 

[Basile]

I don't know they've been in the big tank since the beginning and urchin colonies are huge lol so i don't know about number, maybe different specie anyway they both seem happy munching away lol. Did aWC yesterday too. And the hatpin lost his spine because of the structure , they were too long to fit and broke off his back every time he whent into it its wasn't a health issu i think , because that was 4-5 months ago. But he just didn't grow them back and thats what promped me to wonder why, maybe he didn't get enought food. So putting him in that macro tank; was an idea.

He should get plenty of energy here lol.

But thanks for the input guys it gives something to research got to look at every possibility, never know. I'll have something to read tonight. Thanks for your time.

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[Oxylebius]

Basile - found this article, Josh got me thinking about the toxin issue, so went looking for info on it and came across this - http://reefkeeping.com/issues/2004-08/rhf/index.php. It didn't cross my mind earlier, but for urchins to regenerate spines not only do they need food, but they need Ca, Alk & Mg. Monitor 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. 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.

I really don't think your structure has anything to do with it loosing its spines. Urchin spines move in amazing angles so that it can get its mouth into the craziest, tiniest cracks in the wild.

You had mentioned that it ate part of your structure, this could be an issue for the urchin. They like to eat all kinds of substrates. Perhaps it is causing a slow death.

Urchins love coralline algae, so yours may as well. My tuxedo devoured all coralline in my home tank and so I'd try to put yours somewhere in your tanks that has it growing.

 

[Oxylebius]

Basile, You like to make your own food, I've seen posts, so you may be interested in this.

Homemade Urchin food: Recipe using eggs, carrots, seawater and agar to make seaweed substitute that sea urchins seem to like better than kelp.

1) Chop up fresh carrots into 1/2 - 3/4 inch pieces and fill to the 4 cup line on the blender.

2) Add two WHOLE eggs, shell and all. Break over the carrots.

3) Add 20 grams of plain agar (not nutrient agar).

4) Add sea water to the 4 cup line.

5) Blend until smooth.

6) Pour into a glass baking dish and microwave until boiling. You will need to stop microwave and stir contents repeatedly.

7) Let cool and refrigerate.

8) When solid, cut into strips 1/2 inch by 4-5 inches.

SERVE: Not too much b/c it can foul the water. If the urchin has not finished it in 48 hours, remove, wait a day and replace with fresh. The mixture in the refrigerator will keep about a week. The recipe can be scaled for more or less food. Try a half batch or less the first time.

 

[Basile]

Basile, You like to make your own food, I've seen posts, so you may be interested in this.

Homemade Urchin food: Recipe using eggs, carrots, seawater and agar to make seaweed substitute that sea urchins seem to like better than kelp.

1) Chop up fresh carrots into 1/2 - 3/4 inch pieces and fill to the 4 cup line on the blender.

2) Add two WHOLE eggs, shell and all. Break over the carrots.

3) Add 20 grams of plain agar (not nutrient agar).

4) Add sea water to the 4 cup line.

5) Blend until smooth.

6) Pour into a glass baking dish and microwave until boiling. You will need to stop microwave and stir contents repeatedly.

7) Let cool and refrigerate.

8) When solid, cut into strips 1/2 inch by 4-5 inches.

SERVE: Not too much b/c it can foul the water. If the urchin has not finished it in 48 hours, remove, wait a day and replace with fresh. The mixture in the refrigerator will keep about a week. The recipe can be scaled for more or less food. Try a half batch or less the first time.

Thats great thanks.

 

[Basile]

Cleaning day

WOW i did a WC yesterday but after moving stuff in today in the pod tank i really needed to clean up, and it doesn't take much time but this is just 2 months of feeding and basic deposit of detritus, i did my WC weekly in there.

This is what it looked like yesterday

Now after cleaning...........

This is what amaze me, see is little beek, there's nothing there, its a reflex, no algae there, its totally a mechanical cause it has nothing , i've moved the algae that was just besides it,

A new resident in the main reef he's in love with the glove coral lol.

.

 

[StirCrayzy]

Mine always tried to scrape the glass too, seemed like a waste.of time, cause like you said, doesn't seem to be anything there. If there was any film on the glass surface I'd see little bite patterns everywhere. The can sense it, there's gotta.be something!

I hope he pulls through, but you prob just convinced him he.died and went to heaven LOL hes livin it up in that macro tank!

I searched my history extensively and can't seem to find the toxin article I remember pertaining to adult urchin combat.
Most toxicity studies are in regard to larval or algal aleopathy, so it seems like a needle in a haystack... But I know I read this somewhere reputable, when my urchin died because it was such a likely explanation for the only two urchin deaths in my tanks over the last 15 yrs. The search continues , it's my "white whale" now.