Pest ID affecting birdsnest and stylos

[Om84]

Hey guys,

I'm not having much luck in the general forum but thought I would ask if someone has encountered anything like this.

My tank is SPS dominant. I just started putting corals into the tank about 6-8 weeks ago. I always use Bayer dip. I don't quarantine in another tank as of yet. However, after this I may need to consider doing that as well.

I have a mix of SPS including montis, birdsnest, stylos, and of course acros.

Over the last 2 weeks I have noticed significant polyp reduction and slow deterioration of all of my birdsnest and stylophora species. I have not noticed significant effect on acros, pocilloporas, or montis yet.

When I removed the colonies there is one species that I noticed come off the coral. They don't come off in vast quantities either but they are definitely the dominant species noted. They look like copepods but they are gray in color. I see them hanging around on the substrate as well (my tank is bare bottom / starboard). I bought a cheap amazon microscope as well to help ID this thing.

I took pics with my iphone and this scope. Sorry for the poor quality. I am including pics of the frags/colonies affected and the bug in question.

My water parameters:
Alk 7.6 - 8.0
Ca 420
Mg 1320
pH 8.3
Salt 34.5

Example of frags affected:





Example of Acros so far unaffected:








Bug in question:

 

[vetteguy53081]

Hey guys,

I'm not having much luck in the general forum but thought I would ask if someone has encountered anything like this.

My tank is SPS dominant. I just started putting corals into the tank about 6-8 weeks ago. I always use Bayer dip. I don't quarantine in another tank as of yet. However, after this I may need to consider doing that as well.

I have a mix of SPS including montis, birdsnest, stylos, and of course acros.

Over the last 2 weeks I have noticed significant polyp reduction and slow deterioration of all of my birdsnest and stylophora species. I have not noticed significant effect on acros, pocilloporas, or montis yet.

When I removed the colonies there is one species that I noticed come off the coral. They don't come off in vast quantities either but they are definitely the dominant species noted. They look like copepods but they are gray in color. I see them hanging around on the substrate as well (my tank is bare bottom / starboard). I bought a cheap amazon microscope as well to help ID this thing.

I took pics with my iphone and this scope. Sorry for the poor quality. I am including pics of the frags/colonies affected and the bug in question.

My water parameters:
Alk 7.6 - 8.0
Ca 420
Mg 1320
pH 8.3
Salt 34.5

Example of frags affected:





Example of Acros so far unaffected:








Bug in question:

This is STN (soft tissue nicrosis) and can be caused my many factors such as:
Often its as simple as flow or light and things overlooked. Often siphoning dead tissue and brown gel will reverse the process.
Some possible triggers of infection are:
- Alkalinity spike
- Temperature spike
- Salinity spike
- Low dissolved oxygen
- Poor water quality related with phosphate levels up to 5 ppm
- Change in water flow
- Additions of sand
- Changes in brand of salt
- Bad test kits giving faulty results
- Levels of minor elements such as Iodine, Potassium, Strontium
- Light intensity
- - Changes in water flow
- Addition of new corals
- - Pesticides
- Airborne Contaminants or sprays

 

[sculpin01]

Those are ostracods. Although there are known carnivorous ostracods, they're not common in the hobby and the vast majority of ostracods seem to be benign. Doing a potassium chloride dip (10 g/L tank water for 5 minutes) will kill them.

However, I'm not convinced that they are the root cause of your tissue loss. What're your phosphate and nitrate levels currently?

 

[Om84]

Thanks for the responses
Phosphate is .05 and nitrate 5 ppm
My concern is why is it affecting birdsnest and stylos only? They are the easiest of the sps bunch. I also have no had significant changes in parameters.

 

[pgroth1]

Something in your tank might like eating the polyps.

 

[Om84]

Something in your tank might like eating the polyps.

That’s what I’m asking about.

 

[Kasrift]

That’s what I’m asking about.

I think he means like a crab, angelfish, or something like that.

 

[BranchingHammer]

ID: I believe that is an ostracod in the video at the end.
I've never heard of them being predatory to coral before, but there could be a species that is. More likely it is feeding on the dead tissue as a scavenger if you see them on the coral skeleton.

My initial thought is: How old is the tank and what was used to start it (dry rock vs live etc)?
Tank not mature enough?
Also, could have been an alk swing?
Any chemicals/contaminants in the water?
Nutrient deficiency (though the acros look healthy)?

 

[Om84]

Tank is new. Tank was started back in March. However I went through ich and went fallow for last 3 months. So I don’t have any fish but have snails as CUC. I dose nitrates and feed the tank for maintaining phosphates. Tank was cycled with live bacteria. Corals started going in about 2 months ago.

I’m just surprised that even if there was an alk swing nothing else was affected but the stylos and birdsnest. I thought they were hardy. I know birdsnest usually first show signs of issues. Maybe that’s what happened. I hope it’s that and not some pest.

I had been dosing by hand and even doing top off by hand. I just set up a DOS for alk and set up the ATO.

Just wanted to make sure I don’t have to dose interceptor or something.

I’ll probably also do an ICP test to make sure no deficiencies.

 

[BranchingHammer]

Probably don't have to dose interceptor or something similar, but could be from parameter swings or not enough usable nutrients in the water column. Seriatopora can be sensitive to parameter swings, and not only alk. Potentially salinity if you are topping off by hand and it's a small tank? Also in a newer tank without fish, it could be difficult to create a robust microbiome in the tank. I've also heard of people who can keep acros but never birdsnest before.

If it was me, I would frag the frags as best as possible and have clean margins at the cut site with sterilized bone cutters to try to stop the spread of the STN/RTN. Then focus on keeping parameters stable (seems like you're already doing this). Things will be easier once the fallow period is over and there are fish in the tank as well.

Just throwing out ideas and hope some of them are helpful. I wouldn't rip the tank apart trying to fix this specific problem since your other corals are doing well. Nothing good happens fast in a reef tank...

 

[Om84]

Probably don't have to dose interceptor or something similar, but could be from parameter swings or not enough usable nutrients in the water column. Seriatopora can be sensitive to parameter swings, and not only alk. Potentially salinity if you are topping off by hand and it's a small tank? Also in a newer tank without fish, it could be difficult to create a robust microbiome in the tank. I've also heard of people who can keep acros but never birdsnest before.

If it was me, I would frag the frags as best as possible and have clean margins at the cut site with sterilized bone cutters to try to stop the spread of the STN/RTN. Then focus on keeping parameters stable (seems like you're already doing this). Things will be easier once the fallow period is over and there are fish in the tank as well.

Just throwing out ideas and hope some of them are helpful. I wouldn't rip the tank apart trying to fix this specific problem since your other corals are doing well. Nothing good happens fast in a reef tank...

Thanks for your advice. Tank is 260 gallon - my first large build. Have had lots of issues so definitely learning and trying to be patient. Used to keep smaller tanks before.

I’m praying whatever the issue is doesn’t affect my acros. I can’t wait to put fish back in. I’m still gonna wait 1 more month just to make sure things stabilize and I’m not having to rip apart the tank because of some pest from hell.

 

[sculpin01]

After a little more research, you seem to have a myodocopid ostracod species. You can see the compound eye (which is pathognomonic) reflecting in your microscope video. Myodocopid ostracods can be predators or detrivores, and although no definite coral predatory species are known, they are an understudied group. There's at least one report of myodocopids attacking a diver in Panama, which is interesting. I have found myodocopid ostracods in coral dips before but just assumed they were herbivorous/detrivorous.

Not saying that they are the culprit but if other causes of tissue loss are excluded, interceptor may be indicated.

BTW, potassium chloride dips at the concentration/time listed above are very effective at killing these.

 

[Om84]

Wow, that’s very interesting.

I see these ostracods on substrate as well. How will KCl dip help manage?

 

[Tonycass12]

Thanks for the responses
Phosphate is .05 and nitrate 5 ppm
My concern is why is it affecting birdsnest and stylos only? They are the easiest of the sps bunch. I also have no had significant changes in parameters.

This is a huge misconception that they are the easier sps corals. They are by far the easiest to get upset with small fluctuations in alk or nutrients, way more so then most acros.

 

[Om84]

This is a huge misconception that they are the easier sps corals. They are by far the easiest to get upset with small fluctuations in alk or nutrients, way more so then most acros.

Yes that has definitely been my experience.

 

[sculpin01]

Wow, that’s very interesting.

I see these ostracods on substrate as well. How will KCl dip help manage?

Nah. That would require interceptor or similar. I just meant as an initial dip.

 

[Om84]

I’ll plan on adding leopards, halichores , and pipefish once fallow is over to see if they can control the population. If I see acros getting affected I’ll probably use interceptor. What dose do you recommend? Same dose used for red bugs?

 

[sculpin01]

You're in new territory here, but yes, I would do the same dose as for Tegastes.

 

[Om84]

You're in new territory here, but yes, I would do the same dose as for Tegastes.

Wanted to post an update to my problem above in case it helps anyone.

I tried more frags of stylos and they all suffered the same fate above. I would start noticing decreased polyp extension over next few days until I start seeing what looks like above with areas losing tissue. The coral would then die over the next few weeks.

I ultimately ended up trying interceptor. I have a 260 gallon (total volume ~300 gallon). I used 1 large dog tablet on week 1, then 2 tablets week 2 and finally 3 tablets on week 3. I used escalating doses to hit harder on whatever was remaining.

I am about a month out from the last dose and tried stylophora again in the last couple weeks. I can say I am not seeing the same problem. I am also seeing more polyp extension on my other acros. I used Interceptor + Praziquantel version that I was able to obtain online without a vets prescription.

This copepod may have been the source of the problem since I have not changed anything. If same problem arises I will report back.

 

[Paris by Night]

Wanted to post an update to my problem above in case it helps anyone.

I tried more frags of stylos and they all suffered the same fate above. I would start noticing decreased polyp extension over next few days until I start seeing what looks like above with areas losing tissue. The coral would then die over the next few weeks.

I ultimately ended up trying interceptor. I have a 260 gallon (total volume ~300 gallon). I used 1 large dog tablet on week 1, then 2 tablets week 2 and finally 3 tablets on week 3. I used escalating doses to hit harder on whatever was remaining.

I am about a month out from the last dose and tried stylophora again in the last couple weeks. I can say I am not seeing the same problem. I am also seeing more polyp extension on my other acros. I used Interceptor + Praziquantel version that I was able to obtain online without a vets prescription.

This copepod may have been the source of the problem since I have not changed anything. If same problem arises I will report back.

How did it end up going?