Long spine urchin losing full spines

[Biff0rz]

I have a long spine urchin that's been in the tank for 5mo now. It's been fine but over the past two days I've noticed it losing quite a few of its spines. The bottom tentacles are still lively and it appears to still be eating. These fell off today (see pic)

 

[BanjoBandito]

So usually not a good sign, and usually a sign of stress in some form or another - something eating or picking at it, swings in parameters, osmotic shock (salinity swings), starvation, low salinity overall....just a ton of causes, but generally "stress". Post your parameters and anything else you've noticed in the last couple days/weeks going on. How old is the tank?

 

[undermind]

I agree, not a good sign. How large is the tank? Has it grown a lot in 5 months?

Long Spine's eat a pretty incredible amount. And they grow fast & move fast. I suspect that we often tend to starve them over time in many of our tanks. I don't have one at the moment but I've had them many times. And if I had one today, I'd add nori daily.

 

[Biff0rz]

I agree, not a good sign. How large is the tank? Has it grown a lot in 5 months?

Long Spine's eat a pretty incredible amount. And they grow fast & move fast. I suspect that we often tend to starve them over time in many of our tanks. I don't have one at the moment but I've had them many times. And if I had one today, I'd add nori daily.

233g/275g tv. It's grown quite a bit in the past 5mo, I'd say doubled in size. So I feed nori, but my tangs get it. How can I target the urchins? If it dies, do I have to worry about it nuking the tank or anything?

So usually not a good sign, and usually a sign of stress in some form or another - something eating or picking at it, swings in parameters, osmotic shock (salinity swings), starvation, low salinity overall....just a ton of causes, but generally "stress". Post your parameters and anything else you've noticed in the last couple days/weeks going on. How old is the tank?

I did a w/c last week, nothing crazy. Sg has been stable, and so has the ATO. The tank is almost 2yrs old, with lots of coraline but not a ton of algae growing on the rocks for the urchins. The tank is almost 2 years old now.

params
35ppt/78*
no3 4.06
po4 0.06
ca 490
mg 1445
dkh 8.46
i2 0.10
ph 7.8-8.0

 

[undermind]

233g/275g tv. It's grown quite a bit in the past 5mo, I'd say doubled in size. So I feed nori, but my tangs get it. How can I target the urchins? If it dies, do I have to worry about it nuking the tank or anything?

OK cool that's a good sized tank. I should also clarify that even though my post above was focused on urchins starving, the dropped spines could be caused by lots of things, like @BanjoBandito said.

Is there much algae to graze on for the urchin in general? Regarding nori, yes tangs would certainly make that difficult. What I often do when I have a large urchin is to add nori after the lights go out. The fish won't feed on it but the urchin will.

And as for how to place the algae, I love these algae pouches from Two Little Fishies

Pouch Feeder for Algae and Frozen Foods - Two Little Fishies

Shop The Best Saltwater Aquarium Equipment & Supplies at Saltwater Aquarium. We Carry Everything you will Need for your Fish Tank.

www.saltwateraquarium.com

I also like wrapping a nori sheet around a rock with rubber bands, but even at night, the crabs and snails may devour the nori before the urchin can get it. If you can "train" the urchin to find that pouch on the glass, he stands a good chance of getting most all of it.

And as far as nuking the tank, that's not much of an issue in my opinion. I've unfortunately experienced several die over the years and they're hardly a blip on the radar in my experience in terms of a "nuking" experience. The bigger issue is the pile of needles

 

[Cory]

Usually means its dying unless a large fish bumped those off.

Ive never had luck with diadema urchins always ended up dying. Iirc my last batch died from dinoflagelets toxins.

Ive now successfully kept 2 decorator urchins (short spine) like a year ish. I reccomend those over the logn spine. But i do have a large uv sterilizer to kill any future dinos.

 

[BanjoBandito]

Do you have any fish that could be picking at it? On the surface it looks like the environment is fine, but obviously something is going on. I agree that I’ve never had success with much outside of tuxedos and pencils. My guess is your long spine has a nutritional deficiency….be it being underfed or not getting the right foods. Urchins seem to remind me of clams to me, they can kinda get phantom die offs. They can drop occasional spines either by knocking them off or something else but if this is a mass drop it doesn’t look good. Try and find someone on here that’s had success with them, maybe even email the guys in Florida that are aquaculturing them to release back into the eco system.

 

[Biff0rz]

Usually means its dying unless a large fish bumped those off.

Ive never had luck with diadema urchins always ended up dying. Iirc my last batch died from dinoflagelets toxins.

Ive now successfully kept 2 decorator urchins (short spine) like a year ish. I reccomend those over the logn spine. But i do have a large uv sterilizer to kill any future dinos.

I've had my fair share of dino, they have since regressed and I have a large UV as well.

Do you have any fish that could be picking at it? On the surface it looks like the environment is fine, but obviously something is going on. I agree that I’ve never had success with much outside of tuxedos and pencils. My guess is your long spine has a nutritional deficiency….be it being underfed or not getting the right foods. Urchins seem to remind me of clams to me, they can kinda get phantom die offs. They can drop occasional spines either by knocking them off or something else but if this is a mass drop it doesn’t look good. Try and find someone on here that’s had success with them, maybe even email the guys in Florida that are aquaculturing them to release back into the eco system.

No fish are bothering it, they all stay away from it lol. My guess at this point is food, there's not a ton of green algae, mostly just coraline and I suspect that's not enough for it. I'm going to try and get some nori by it tonight and see how it does.