some small holes on emperor angel and lateral line

[BengBear]

Recently, I realised that there are some small holes (1mm dia) on the emperor angel. On its head, around the eyes and cheek and some part of lateral line having small scratch.

Are these damages caused by banging too hard against rocks, searching too hard for food in narrow rocky places or some nutriension issue?

[leebca]

The most likely cause is nutritional needs aren't being met.

The large Angels are very susceptible to this. They first off are often stress in captivity because of lack of space. An adult large Angelfish needs about a 500 gallon aquarium to have enough space. You can see that right after nutritional issues, stress is the next most likely cause

In order of what I think is most likely:
Vitamin deficiency (A and/or C); Poor Nutrition
Chronic Stress
Poor water quality (including high levels of dissolved organic matter and/or nitrate)
Activated carbon (either removing something the fish need or the dust clogging the pores on the fish)
Retrovirus
Hexamita
Amyloodinium-like dinoflagallate
Stray Voltage (is your system grounded properly?) [the article below disagrees with this one]

This article is a lengthy discussion of this condition that you may wish to read if you want to learn more.
Marine Head & Lateral Line Erosion: A Description of the Syndrome and a Review of its Speculated Causes by Steven Pro - Reefkeeping.com

[BengBear]

thanks for advise.
I feed them with Dr Bassleer's Forte Biofish food which contain
Vitamin A 17000IU/kg
Vitamin D3 3000IU/Kg
Vitamin C 250 mg/Kg
Vitamin E 400 IU/Kg
Copper 30mg/Kg
and others proteins, Antioxidant
I had been feeding them for about 1 year with the above and they were alright until I switch it to ReefMax which claims it contain Vitamins (with no details) for some 2months. Notice the holes problem some 1 month ago and the water Nitrate was 20ppm or less. (don't think is the nitrates as it was around this level during the 1 year period)

This is when I started to feed Kent Marine Zoaplex and nitrate increase suddenly to 140ppm. Changed 25% water and added AZ-NO3 (for 3 days), and Nitrate is around 80ppm. Reverted to Dr Bassleer food after reading your article.

Result: emperor angel is still having holes unheel yet. But nothing seems to go wrong with Koran and yellow angel, Regal and Naso Tangs.

pH is stable around 8.4 to 8.6. Other fish only parameter are about normal.

I am not sure, how long do I have to wait for the heeling to take place.

Any suggestion.

[leebca]

The healing rate is somewhat connected to how far the condition has advanced. The longer the condition has persisted, the longer the recovery even if everything is perfect.

The healing is also relative to how perfect things have become. If there is still some lacking in the nutrition, environment, water quality, the slower the recovery to the point of no recovery.

I would say that if the cause is corrected and the fish has been affected for the 2 months, with the 1 month showing, then recovery should be evident in a month, with full recovery maybe taking a few more weeks or a few more months. That is to say, recovery varies so much in these cases, not much else can be said for this. HOWEVER, some noticeable degree of recovery should be evident within a month.