Gray discoloration, Bicolor Blenny

[Resilient]

I have a bi color blenny, had him in the tank a little over a month now. Today I noticed a lighter gray patch that seems to have grown throughout the day. I spent 30 minutes trying to catch him to get him into a quarantine tank, but no success. He is an expert in the rockwork.

Trying to figure out how critical it is I get him out and treat him. He is acting normally and eating.

He is hiding from me now that I spent awhile trying to catch him, but here are the two best video clips I got of him. He manages to do a good job of hiding his left side which is where the marks are, but pausing at the beginning of the 1st video, or playing on slow motion is probably the best view:

 

[CoralB]

Trying to see the gray spot you are taking about . Is there a way to magnify him and keep him steady while shooting ?

 

[Resilient]

I have been trying to get him still and zoomed in, but he is quite skittish after trying to catch him. Here is a screen grab from about 1 second into the 2nd video that highlights the area:

 

[vetteguy53081]

I have a bi color blenny, had him in the tank a little over a month now. Today I noticed a lighter gray patch that seems to have grown throughout the day. I spent 30 minutes trying to catch him to get him into a quarantine tank, but no success. He is an expert in the rockwork.

Trying to figure out how critical it is I get him out and treat him. He is acting normally and eating.

He is hiding from me now that I spent awhile trying to catch him, but here are the two best video clips I got of him. He manages to do a good job of hiding his left side which is where the marks are, but pausing at the beginning of the 1st video, or playing on slow motion is probably the best view:

The area you mention looks to be a scrape injury which is in alignment with them often darting into rock and crevices as they spook easily. Both videos have low light and perhaps still pics utilizing Bright white light, no blue will help confirm

 

[CoralB]

The area you mention looks to be a scrape injury which is in alignment with them often darting into rock and crevices as they spook easily. Both videos have low light and perhaps still pics utilizing Bright white light, no blue will help confirm

Agreed !

 

[Jay Hemdal Verified Community Expert]

I have a bi color blenny, had him in the tank a little over a month now. Today I noticed a lighter gray patch that seems to have grown throughout the day. I spent 30 minutes trying to catch him to get him into a quarantine tank, but no success. He is an expert in the rockwork.

Trying to figure out how critical it is I get him out and treat him. He is acting normally and eating.

He is hiding from me now that I spent awhile trying to catch him, but here are the two best video clips I got of him. He manages to do a good job of hiding his left side which is where the marks are, but pausing at the beginning of the 1st video, or playing on slow motion is probably the best view:

It does look like an injury - being on one side and all. The fish is breathing a bit fast, but blennies often breath fast when actively swimming.

I doubt that it is an injury from the rocks - that just doesn't happen. Blennies are supremely adapted to living on and in rocky areas, they just don't injure themselves that way. More likely, this started as an injury from a tankmate. It may or may not have a secondary bacterial infection going on - but your note that it grew in size after you first saw it does point to that.

Given how difficult these fish are to catch without harming them, and given that it is unlikely to be contagious, I would just leave it for now.

 

[Resilient]

I woke up this morning and it got significantly worse, he almost certainly will not make it, but I need to know if I should be concerned/anything I should do for the other fish in the tank. At the moment, everyone else seems fine. Here is what it progressed to overnight:

 

[Jay Hemdal Verified Community Expert]

I woke up this morning and it got significantly worse, he almost certainly will not make it, but I need to know if I should be concerned/anything I should do for the other fish in the tank. At the moment, everyone else seems fine. Here is what it progressed to overnight:

Sorry to see.

I’ve seen this virulent lesion on gobies and canary blennies. It usually starts with a minor injury that then gets infected with bacteria that’s already present in your tank. It isn’t contagious, but very difficult to treat due to how fast it progresses.