Blastomussa receding tissue
 

One of my Blastomussa started showing receding tissue and exposing skeleton today. This is the second Blastomussa I've had issues with this year. Last time this happened... had a nice 5-6 head colony that looked great for a week with good polyp opening and colour, eating frozen brine shrimp, and then it just started to expose skeleton and its tissue fell off the skeleton. That one died. I thought I killed it by putting it too close to the light off the start. My next two specimens, I placed deeper in the tank. About 8 days ago, I consolidated my two smaller reefs and put everything into a larger tank. I thought my Blastomussa had adjusted, but one of the pieces I overlooked and again placed too close to the top of the tank. Now it looks like this...

http://sphotos-f.ak.fbcdn.net/hphoto...29634608_n.jpg

Finally, now doing some web searching. I just read that Blastomussa are actually surprising tricky... having very latent reaction to stress, and typically thought to be due to being exposed to bright light too quickly.
Reference link
It's been 8 days since I moved my 2 tanks into one big reef, and it was showing good health, eating brine shrimp, and good colour. But 8 days later it's showing stress. Bugger. I've just moved it to the sand bed, might be too late. Good thing my other big colony is in a dimmer spot and I didn't get too ambitious moving it into the limelight.

Anyone else with similar experiences with Blastomussa?

Not sure if this helps...is your water really clean? The reason I ask is that I've read blastos also come from turbid waters, so they tend to like things on the dirty side. I've also heard from people who tried keeping blastos in their clean water sps systems, blastos never last very long for them.

Also any chance your hermit crabs or some other critter like a fish may be picking on the blasto's mantle? When ever I see damaged tissue on a blasto I do a quick lugols dip to try and stave off infection and hope for the best.

Usually I find my blastos do this if they are under fed or getting hit with too much flow. Try feeding them Acan+. They love it and they thrive on it.

Where do you buy acan plus Steve?

JMes here on the forum makes it. I got mine from him. I'm not sure who oin the lower mainland carries it but a bunch of the stores in Alberta carry it. Send JMes a PM and see if he can help you out.

Thanks Steve

What tankmates do you have in there? Another possibility to consider is that someone could be picking on them.

hmm... lots of interesting perspectives and ideas... it looks today like it did yesterday, but now in a more sheltered part of the tank.

Clean... yes and no. I do 30% water changes weekly for the sake of trace elements, and use a skimmer that produces a few centimeters of collection daily. However, I don't use a phosphate reactor, not any kind of filter/sump, feed frozen food liberally... I don't think there's a lack of carbon/proteins in the water.

negative on being grazed, never witnessed.

I've been using frozen brine shrimp enriched with spirulina... there's lots of HUFAs there.

Inhabitants have not been observed to nip at corals. They are:
Synchiropus splendidus
Synchiropus picturatus
Plectranthias inermis
Neocirrhitus armatus
Gramma loreto
Acanthurus leucosternon

Added today:
Naso lituratus
Zebrasoma flavescens
Paracanthurus hepatus

I still like my over (too soon) exposure to bright light theory with latent stress manifestation. The first Blastomussa merletti that I lost was placed about 8 inches from the surface under a 250 watt metal halide... which looked great for a week before tissue deterioration. Expulsion of zooxanthellae rich mucus out of their mouths was seen around day 2... despite another 5 days looking great with full polyp extension. This particular specimen currently in trouble... was ok upon acquisition when placed about 16 inches from surface and semi-shaded under a 150 watt (not 250w) metal halide for two weeks or so, but then relocated to another reef tank to a spot (too ambitious) about 10 inches directly under a 92 watt (Innovative Marine) Skkye Tablet LED which is visually brighter than the 250 watt metal halide... no expulsion of zooxanthellae was observed (might have missed) but looked great with full polyp extension over the last 8 days, and still looks good on polyp extension aside from the skeletal exposure showing since the 8th day. Meanwhile I have another Blastomussa (Rainbow) that was conservatively placed in the periphery of the lighting in the new tank with same water quality and tank mates... no issues.

PS-thanks all for your thoughts.

Yeah I wouldn't guess any of those fish to be suspect in this case. Just thought I'd ask though, because in the past I had similar issues with blastos, and it was naughty fish in my case. Good luck getting it sorted. My thinking on this is that it can come around, try feeding the Acan+ as suggested, it does seem to help them out if they're hungry. With that said I don't target feed mine, but on the flipside, maybe I have a dirty overfed tank :lol: