pls help RTN or STN

[damien_kee]

to all the bro,
this is my 1st post in this forum!
can some1 pls tell me how to make sure that is RTN or STN? when the tips of acropora is soften (like no CA skeleton inside) is this STN? coz my acropora is like this since last friday.

 

[jetaero]

hmm... like it's hollow? Stn is where it slowly turns white moving along the branches... RTN is where the whole coral turns white in a day...

-Josh

 

[damien_kee]

thanks for ur reply bro. yup! feels like its empty inside. I frag it n remove the parts with the inner empty. hhmmm... wonder would it help or not... :doubt:

 

[NaH2O]

damien_kee - any chance of posting a photo? If the tissue is gone and all that's left is skeleton, then I would frag it off. It's not new growth is it?

Welcome to Reef Frontiers!!!

 

[kevinpo]

What type of coral are you talking about? Soft coral or stony corals such as Large Polyp Stony (LPS) or Small Polyp Stony (SPS).
A picture would be helpful too. RTN/STN most often refers to SPS corals which have only a very thin layer of tissue covering the outside of their skeleton. This can peel leaving the white dead skeleton exposed. If is peels quickly (24 hours or so) then we call it RTN. If it happens over a week or more we call it STN.

Regards,
Kevin

 

[damien_kee]

bro NaH2O, here is the picture im juz taken. the tissue is still remain, but it look empty inside, the area where i round up with red color is the suspect! hope my picture show clearly to u.
it is not a new grow!


thanks!

 

[damien_kee]

the first pic show the original polyps extend nicely... but not now. & the 3rd pic show the yellow goby I have staying with my acropora millepora. alots of ppl say that this fish no good for acropora (but I dun kno how to remove it fr my tank).

my tank spec:
2 feet tank.
2 X HO T5 lighting 1 X power grow FL
am:0
NO3:below 0.25
ph:8.4
kh:10
mg:1300
ca:400
temp:28C
sal:1.024

I place my acro at the highest of my tank, the distance between acro & light is about 5~6 inch.

 

[damien_kee]

What type of coral are you talking about? Soft coral or stony corals such as Large Polyp Stony (LPS) or Small Polyp Stony (SPS).
A picture would be helpful too. RTN/STN most often refers to SPS corals which have only a very thin layer of tissue covering the outside of their skeleton. This can peel leaving the white dead skeleton exposed. If is peels quickly (24 hours or so) then we call it RTN. If it happens over a week or more we call it STN.

Regards,
Kevin

bro kevinpo, Im talkng about sps, acropora millepora. sorry for causing so much unclear info. Im suspect STN.
hope all the expert & bro can give me the answer & solution.
thanks! thanks!

 

[mojoreef]

I would say its not either. RTN and STN is where the tissue is actually peeling off the coral. I dont see that in the pictures. The way corals lays down calcium is by creating a thin shell during the dark hours and then filling in during the days. Is your calcium and alk level ok?? is the tissue coming off the corals and I just cant see it??

Mike

 

[damien_kee]

I would say its not either. RTN and STN is where the tissue is actually peeling off the coral. I dont see that in the pictures. The way corals lays down calcium is by creating a thin shell during the dark hours and then filling in during the days. Is your calcium and alk level ok?? is the tissue coming off the corals and I just cant see it??

Mike

ic. thanks bro,
the tissue still attach to the skeleton.
the polyps is retract.

p/s: would u say this is normal? :eek2:

 

[mojoreef]

Well polyps come out for different reasons, basically mechanical or chemical responce. Have you looked at the coral at night to see if they are extending then?? are all the polyps not extending or just in that area???


Mike

 

[kevinpo]

The coral looks healthy but perhaps damaged (looks OK to me) by the clown goby. They can nip at the polyps of the coral causing them to retract.

A. millepora often grows very fast and at the tips where the new growth is there can be little polyp extension. Also note that the color may be very different (usually pale or white) at the tips where the new growth is occurring.

Regards,
Kevin

 

[StoneyK]

Dont know what it is but would be interested in knowing as well, the same sort of soft puffed out hollowed out thing happend to one of my corals at one tip( an unidentified stag). It almost crumbled/flaked away at the touch. I just niped it off and a new tip formed with no problems.

 

[damien_kee]

Well polyps come out for different reasons, basically mechanical or chemical responce. Have you looked at the coral at night to see if they are extending then?? are all the polyps not extending or just in that area???


Mike

I C.
at night, not much change. extend same like daylight. not all polyps, but some of it.
coz this is my 1st acro, mayb im extra worry. :lol:

 

[damien_kee]

The coral looks healthy but perhaps damaged (looks OK to me) by the clown goby. They can nip at the polyps of the coral causing them to retract.

A. millepora often grows very fast and at the tips where the new growth is there can be little polyp extension. Also note that the color may be very different (usually pale or white) at the tips where the new growth is occurring.

Regards,
Kevin

Thanks bro. Thanks for that useful info...

 

[mojoreef]

Yea I would lean more towards the gobies causing damage then a problem with the coral

good luck

Mike

 

[Electrokate]

Hi,
You can catch the goby, I had to catch mine after watching it eat all the polyps off my acros- many of which did rtn shortly after. I gave my fish to a guy here in Oly with a softie tank, if you are in the Puget Sound area he will give yours a good home too. They can't help it, they clear a bit of acro to lay their eggs on. I think captivity makes them alter their behavior. They perhaps expect the offspring but don't have a mate so keep clearing and clearing in hopes of attracting one. Just my speculation. Green clown gobies single or not never gave me this trouble, just the one single yellow one. Maybe it's the yellows plus being a single fish.
If you have a large tank and a coral or cave it really likes try slowly lifting the coral with the fish in it slowly with a net under it til the net is mostly around and under the coral. Lift the coral out and hopefully the fish will let go. Or if the fish doesn't hide in a specific coral or rock have a friend tease it into a corner where you have the net below the fish, raise the net up real fast under it. That's how I got mine out. Took half an hour but it was worth it. Only broke off 5 digitata frags which I glued to a rock and sold to an LFS for 20 bucks. I'm happy! And my friend loves his free fish.
Kate

 

[damien_kee]

Hi,
You can catch the goby, I had to catch mine after watching it eat all the polyps off my acros- many of which did rtn shortly after. I gave my fish to a guy here in Oly with a softie tank, if you are in the Puget Sound area he will give yours a good home too. They can't help it, they clear a bit of acro to lay their eggs on. I think captivity makes them alter their behavior. They perhaps expect the offspring but don't have a mate so keep clearing and clearing in hopes of attracting one. Just my speculation. Green clown gobies single or not never gave me this trouble, just the one single yellow one. Maybe it's the yellows plus being a single fish.
If you have a large tank and a coral or cave it really likes try slowly lifting the coral with the fish in it slowly with a net under it til the net is mostly around and under the coral. Lift the coral out and hopefully the fish will let go. Or if the fish doesn't hide in a specific coral or rock have a friend tease it into a corner where you have the net below the fish, raise the net up real fast under it. That's how I got mine out. Took half an hour but it was worth it. Only broke off 5 digitata frags which I glued to a rock and sold to an LFS for 20 bucks. I'm happy! And my friend loves his free fish.
Kate

wow! expert technique... ha.... not sure would i success... thanks bro...

 

[Electrokate]

Hi,
I am anything but an expert fish catcher! It can be very hard. But these guys are not very smart and not as prone to diving deep in the rocks when you tease them a little. Wish I was an expert, I would get the bully bangai out...
Good luck!
Kate

 

[damien_kee]

Hi,
I am anything but an expert fish catcher! It can be very hard. But these guys are not very smart and not as prone to diving deep in the rocks when you tease them a little. Wish I was an expert, I would get the bully bangai out...
Good luck!
Kate

wow! bro, u study them alots? u r the
btw, thanks for sharing the way to did it... thanks alots!