Blastomussa receding tissue

[Reef_Geek]

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

Originally Posted by RESONANCE

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.

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.

Originally Posted by ScubaSteve

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.

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

Originally Posted by Delphinus

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

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.