Grouper problem

[sumthin fishy]

Not sure if I should post this in the noob section or not : My brother has been keeping saltwater(fowlr) for about 5 years and it's a question for him, but Ive never kept SW, so technically Im not even a noob yet Well here goes:

He used to have a grouper(not sure what type) and it used to get splotches of scales missing on its head. It died a few months ago, possibly from those injuries. He got a v-tailed grouper to fill the void the other one left. He also took out one of the large rocks he had. This rock had some sharper edges, and he suspected this is what caused the damage to the origional one. He was wrong. The new grouper is now showing the same problem. The only other tankmate at the moment is a moray(seems to leave the Grouper alone) that is still a little baby, 6-7" and the v-tail is about 4". Its only a 29 gal, and after I did some looking on the morray he's deciding to get rid of it here soon. Any ideas what is causing it? how to fix it?

 

[Max]

Let me ask you a couple of questions about the set up and it will help get you a better answer. How long has the tank been set up how much l.r.is in the tank and how is it designed, what are the water readings, what does he feed how often etc? I'm going to go out on a limb and take a wild guess. Are there places where both fish can have a ,"safe", space? I don't know anything about the v-tail but, morays do quite a bit of noctural activity also, if it felt the grouper had invaded it's space it would show some aggresion. I'm not saying that it's biting the other fish but, it very well may be panicing the fish. I'm guessing but, that would also explain the missing scales on the other ones head too. How many scales are missing from the current fish and how many were missing from the other at the time of it's demise? If it were another cause other critters would be affected .
A lot of this is just guess work based on exp from other people and one incident in my own tank involving a tomato clown and a gramah that it took a disliking to. It showed similar signs of head trauma and missing scales. It took me weeks to figure out what was going on until one afternoon I came in and saw it brain it's self after being chased away by the tomato.
Just a quess & hth
Chris

 

[sumthin fishy]

I actually just found out he doesn't have LR.(sorry) Its been running for about 2 years. There is a few rocks to hide in. Only thing is, the morray wasnt in the tank when the other one died, but there were other fish(he sometimes grows out stuff for our sisters 100 gal). I recall the last one had more than 50% of its head showing the damage. The morray doesnt show the same problems. If we really need a water reading, Id have to go over there and take one myself(and buy a kit for that, since my bro doesnt do that). Is there anything that you salt people do for injuries like this? Its not like you can just add NaCl like I do in my FW tanks lol.

 

[Max]

The best thing to do is remove what ever it is that is causing the issue. Do you know if he does regular water changes and general tank maint? Does it just look like missing scales or does the head look like it's eroding or melting? It could be due to very poor water conditions or a parasite. He should probably remove the injured/sick one put it in a hospital tank and treat with melafix there are also some anti biotic fish foods avail. I wouldn't use either though unless I saw signs of infection. I'd stongly urge your brother to start testing his water conditons he'll find that it will universally improve the health of all his critters.
Sorry, I can't give you a better answer
Chris

 

[Crown Royal]

Do the missing scales on the head look like holes rather than having been ripped out?

Just a shot in the dark, but perhaps it could be hole-in-the-head syndrome. A common affliction of tangs in SW and discus in FW. It is generally thought to be caused by prolonged exposure to poor water conditions and poor diet. I'm not sure whether groupers are known to be susceptible.