Arius Seemani--urgent

[Bowling_Fleury]

Okay last night I noticed my sharkfish Freestyle had a damaged dorsal fin. I didn't think much of it because Freestyle looked happy. But then today I'm seeing Underscore with a damaged one too. It looks almost torn, but there's no discoloration so not really like fungus. They are tankmates with a Scooter Blenny.

If you have any suggestions please help me. I'm very sad. Sharks are my favorite saltwater fish.

 

[WILDER]

Size of tank in gallons or litres.
How many fish in there.
Water atats in ammonia,nitrite,nitrate,and ph.
How much of the fin is gone, any red streaking in the fins.

 

[Bowling_Fleury]

The tank is a 10 gallon, with 3 sharks and one blenny. There aren't any red marks around the fin, and only the tips are missing. I'm not sure on the stats but I'm pretty sure they haven't changed the last time I cleaned the tank and this just happened a couple days ago.

 

[WILDER]

Don't know what type of fish a blenny is.
What type of sharks are they are some are aggressive.
Plus your tank is way to small for them this is why there probably being aggressive.
Post water stats please.