Blue Linkia Starting Necrosis?

[David35]

Hi Dr. Ron, thanks for any advice!
I've had a healthy blue linkia for over half a year (so I know the introduction to the tank went well). The tank is 55g w/ 125lb LR, crushed coral substrate, BakPakII skimmer, millenium2000 charcoal filter, temp 79. In the last month he's been more shy than usual - very hard to find. He's out today and to my shock he's got orangish necrosis (I'm guessing that's what it is) on two of his arm-tips.
I recently introduced a chocolate chip star but doubt that has anything to do with it...Should I remove the arms? If so how? What could be going on? I do 10 percent water changes weekly. Nitrates are much higher than I'd like and I've been trying everything (cut down on food, lights (there are no corals), increased water to 20 percent changes weekly, added that charcoal filter, added a PhosZorb as I was getting red slime and still have some of it...Also running a nitrate sponge. yet I still have nitrates at 160 ppm! Next step is to somehow remove the crushed coral and put in LS. I know I've spewed a lot here but I'm hoping something I've said will give you a clue...
Many thanks!

[rshimek]

David,

Don't panic and do anything drastic. Stars are very reslient creatures if their environment is to their liking so it may heal itself. Above all, don't go hacking at it.

Describe the "necrosis" as completely as you can to me, so that I may visualize it better.

[David35]

well I'd say 1-2 centimeters starting at the very tip of the top side of two arms (the finger tip side) are pretty bright orange. On close examination it looks like that orange/white color the same as "Push Ups" we used to buy from the ice cream truck (orange sherbet?) I haven't lifted the star out of the tank. I will note that it is very unusual that the last month mine has been hidden. Mine is a pretty social guy compared to others that I have read about.

The texture on the top side of the arms, where the orange is, may be of interest. As best I can describe it, it's like a rasberry -- lots of tiny bulbs that make up the orange surface -- perhaps a different texture entirely than the star itself. Maybe this is a growth? the clusters that make up the rasberry look are much smaller than an actually rasberry but it's the same concept -- lots of little "bulbs" making up the whole of the affected area...

Maybe it's a fungus? It's very noticeable! Many thanks, David

[rshimek]

Hi David,

Is there any possibility you can get a good close-up photo of this and post it?

Barring that, I will suggest that you simply observe it for the next week or so and get back to me then.

Stars, like other complex animals, get diseases and often they can fight them off if left alone.

DO NOT do any of the barbarous treatments such as "iodine" or "fresh-water" dips on the animal. If it is not dying (and I don't think it is), those treatments will make sure it is.

[David35]

A friend has a digital camera I might be able to borrow. If so I certainly will post it. Silly question, do I just cut and paste it in this message window?

Thanks. I will keep you posted w/or w/out photo.

[Minotaur15]

Originally posted by David35
I recently introduced a chocolate chip star but doubt that has anything to do with it...

I got a crisp new dollar that says it does. :D

I've seen CCs eat many a things, including other CCs, so if it were me, I'd be watching the CC more closely. But, thats just my uninformed experience. ;)

{waiting to get slammed by the doc} :blown:

BTW, if this is a reef, good luck keeping him from eating other things. :(

[rshimek]

Originally posted by Minotaur15
Originally posted by David35
I recently introduced a chocolate chip star but doubt that has anything to do with it...

I got a crisp new dollar that says it does. :D

I've seen CCs eat many a things, including other CCs, so if it were me, I'd be watching the CC more closely. But, thats just my uninformed experience. ;)

{waiting to get slammed by the doc} :blown:

BTW, if this is a reef, good luck keeping him from eating other things. :(

LOL! I won't slam you for mentioning the negative effects of CC stars. Bad news critters, but given the odd pattern of discoloration, I doubt it was caused by the other star's attempts at predation. That's why I didn't mention it in my answer. Maybe so, though. :D

[David35]

Well I still don't have that camera though I hope to have it w/in 24 hours.
The starfish was on top of a pointy rock with all legs "poured" down the sides so I took it out for closer examination. There's absolutely no change. Still has 1 cm splotches that I'm thinking now are more along the lines of legions or ulcers. Two of them total on two separate finger tips, along the top and side.

It's amazing how expressive this creature is for not having a brain. It's when I do something like add new water near it it gets wrinkley and just looks bothered. Then 15 minutes later it's stretched out again and beautiful.
A couple other thoughts: I do have two urchins but they have lived fine together since day one, which is six months ago. I wonder if since I increased my filtration and added the phos zorb and Nitrate sponge that perhaps it's not getting as much food. It does look a little skinnier than usual.

[Brett]

Originally posted by David35
It's amazing how expressive this creature is for not having a brain. It's when I do something like add new water near it it gets wrinkley and just looks bothered. Then 15 minutes later it's stretched out again and beautiful.

This might be part of the problem. Blue Linkia stars are notorious for being very sensitive to changes in specific gravity - hence the need to acclimate them very slowly. If you're adding new water that has a slightly different SG (or even worse, adding freshwater for a topoff) near the star then you could be damaging it this way.

HTH,
Brett

[David35]

Thanks, I thought about that and generally try to avoid the star when adding new water. And I do my best to get the salinity equal to that of the tank, which is at 1.020 btw.

[rshimek]

David,

Your last answer gives a major clue. I should have asked sooner about the salinity.

The salinity is WAY too low for continued health of any echinoderm. A specific gravity of 1.020 gives a salinity equivalent to the upper reaches of an estuary, and these animals evolved in and need full strength sea water. This means a specific gravity of 1.025 or so, depending on your system's temperature. I would suggest raising the specific gravity to reef normal levels over about a 3 or 4 day period.

This article will help explain why you need to have them at natural sea water salinity.

http://www.animalnetwork.com/fish2/aqfm/1998/april/wb/default.asp

[David35]

Ok Dr. Ron,
But before I adjust salinity let me refer to a statement from the article you just linked, and follow with a question:

{For the aquarist this means that full-strength salinity (between 35 and 37 ppt or, generally, specific gravities between about 1.024 and 1.026, depending on the temperature) is necessary for successful maintenance of most echinoderms.}

I thought I read that those standard salinity measuring devices (plastic rectangular "cup" with plastic arm that frequently gets bubbles on it and can lead to messed up readings if one is not careful to check for the bubbles) are set for certain tank temperature (either 78F or 80F, I can't remember which) and that for every degree off from there the salinity scale becomes more and more inaccurate. So if my tank is at 79 and it reads 1.02, what's my actual salinity? Also, how would you most recommend raising the salinity specifically -- add highly concentrated salt mix to small amount of water and add it throughout the tank? How much mix should I add for a 55 gallon tank to get it from where I am now to where I need to be? Thanks.

And adding in my humble defense, the salinity has been reasonably constant since day one in my tank. I only top off the tank with RO water with appropriate mix added -- no fresh water, for example. So if the problem is based on salinity, it's curious that it didn't happen sooner though certainly it is a possible cause of the problem.
Many thanks.

[LiquidShaneo]

I believe this is the cart you are looking for:

http://www.animalnetwork.com/fish2/aqfm/1997/nov/features/1/default.asp

hth

liquid

[David35]

thanks LS.
I'm going to increase my tank to 80 and increase salinity to at least 1.023 if I can get it there...absent any other direction, I'll take out a quart or so of tank water, add a 1/2 cup to a cup of mix, stir, then return it to the tank. I'll do that daily until I get it the salinity up.
I'll know I've made it when I see my linkia send off a comet. That would be exciting!

[rshimek]

Hi David,

[QUOTE]Originally posted by David35 /quote]
I thought I read that those standard salinity measuring devices (plastic rectangular "cup" with plastic arm that frequently gets bubbles on it and can lead to messed up readings if one is not careful to check for the bubbles) are set for certain tank temperature (either 78F or 80F, I can't remember which) and that for every degree off from there the salinity scale becomes more and more inaccurate.

These devices are "temperature corrected" to cover pretty much the whole range of tank temperatures. This is done by having them made of a plastic which is relatively insensitive to temperature, and so it doesn't change shape much over that range.

So if my tank is at 79 and it reads 1.02, what's my actual salinity?

Very close to 29 ppt, or about 3/4 of normal sea water. A temperature-specific gravity-salinity conversion table is given in the article at this URL.

http://www.animalnetwork.com/fish2/aqfm/1998/april/wb/default.asp

Also, how would you most recommend raising the salinity specifically -- add highly concentrated salt mix to small amount of water and add it throughout the tank? How much mix should I add for a 55 gallon tank to get it from where I am now to where I need to be? Thanks.

I would let the tank lose water through evaporation and make up the replacement with normal strength sea water.

...it's curious that it didn't happen sooner though certainly it is a possible cause of the problem.

I would suggest the problem has been brewing for a long time, and that you are finally seeing the manifestations of it. These animals can use a phenomenal portion of their body's energy budget to maintain an internal ionic environment. When they run out of reserves, however, that is when things start to appear. They literally have been drained of energy by the fight to keep their internal environment in the correct range.

[David35]

"I would let the tank lose water through evaporation and make up the replacement with normal strength sea water. "

But Dr. Ron, won't that take a long, long time (even with weekly water changes also using corrected levels of salt)?

You had said previously that you would recommend increasing salinity over a "three or four day period."

I don't mean to pester you, I just want to get this right. I do recall reading once that salinity must be raised very gradually, but I think you have given me contradictory advice....

[rshimek]

Hi David,

Originally posted by David35
"I would let the tank lose water through evaporation and make up the replacement with normal strength sea water. "

But Dr. Ron, won't that take a long, long time (even with weekly water changes also using corrected levels of salt)?

I guess that depends on how much you lose in evaporation water. I lose about 2 gal per day out my lagoonal reef in a 45 gal. Over the course of a week I move the salinity a lot.

You had said previously that you would recommend increasing salinity over a "three or four day period."

You can hurry this along. Do a series of 10% to 15% water changes, with the new water being at the salinity that you are targeting for. Let it evaporate in between time. This way you wouldn't be moving it too drastically, but you still should be able to get it into the good range within a few days. This will be a lot of work.

I don't mean to pester you, I just want to get this right. I do recall reading once that salinity must be raised very gradually, but I think you have given me contradictory advice....

I really didn't but gradualism when moving away from the extremes can take so long that the animals can perish. Most organisms can take fluctuations of 1-2 ppt per day pretty safely. In this case, gradual means changes over a day, not weeks.