Is there a problem with my fish

[VikS]

Hi, one of my 5 Anthias has its fins a bit torn up. Another rhomboid wrasse also looks a bit rough. The tank is heavily stocked with 20-30 fish.

Is this a sign of a disease? Flukes? Or just aggression from another fish? Pics of Anthias and a video also attached.

 

[Sharkbait19]

Looks like aggression to me. Have you noticed any fish being mean to others? Setting a camera in front can work to find the aggressor.

 

[vetteguy53081]

Hi, one of my 5 Anthias has its fins a bit torn up. Another rhomboid wrasse also looks a bit rough. The tank is heavily stocked with 20-30 fish.

Is this a sign of a disease? Flukes? Or just aggression from another fish? Pics of Anthias and a video also attached.

What size tank and age of tank ?
Looking at pic, it appears there is shredding of the tail and finnage going on. Any more off the tail and fish will be unable to swim properly.
While I see a couple of the fish in video- What other fish are in the tank with it?

If you have not seen physical damage being inflicted by a tankmate, you can set your cell phone on video mode for about 40 mins and drop a little food and walk away - YOU MUST walk away as they know youre there. Often the aggressor is a jerk at feeding time.
Review the video and see who it may be

 

[VikS]

Thanks, I will keep an eye. It is a 200gallon tank. Established 2 years and these fish are probably closing a year in the tank now. There are mostly tangs and wrasses.

Most likely culprit is the male Anthias (it’s a group of 1 male and 5 females). Though I have not seen any aggression between the fish except the yellow and purple tangs.

Other possibility is that I have some sort of killer hitchhiker.

 

[Jay Hemdal]

Thanks, I will keep an eye. It is a 200gallon tank. Established 2 years and these fish are probably closing a year in the tank now. There are mostly tangs and wrasses.

Most likely culprit is the male Anthias (it’s a group of 1 male and 5 females). Though I have not seen any aggression between the fish except the yellow and purple tangs.

Other possibility is that I have some sort of killer hitchhiker.

Flukes can make a fish look sort of tattered, but not this severely - I’d say tankmate aggression here. Tough to catch this because while you are watching the fish, they stop fighting to watch you.
Try the phone trick!

Jay