Endli bichir has white threads stuck on mouth

[fishmarket]

Have you tested your water?

No

If I did not test my water...

...I recognize that I will likely be asked to do a test, and that water tests are critical for solving freshwater health problems.

Do you do water changes?

Yes

What percentage of water do you change?

41-50%

How frequently do you change your water?

Every week

If I do not change my water...

...I recognize that I will likely be recommended to do a water change, and water changes are critical for preventing future freshwater health problems.

Is it food? Is it worms? Injury? Appeared overnight. Bichir is eating and behaving normally. Water change weekly. Had him a little over a year since baby, he is now 13 inches. See photo attached. P.S. I grow out algae for sides and back of tank so it's not neglected and dirty.

 

[Caveden]

It looks like worms, external parasite kno4te

 

[kno4te]

Little hard to tell. What have you been feeding? Tilapia? I’d net the fish and pull it off/out. If it’s a parasite then removing it will cure it.

 

[Fallen_Leaves16]

Little hard to tell. What have you been feeding? Tilapia? I’d net the fish and pull it off/out. If it’s a parasite then removing it will cure it.

But removing an unknown external parasite by force can oftentimes do more harm than good, especially if the parasite has a complex anchoring mechanism that's firmly ingrained into the flesh- by pulling off the parasite, it can potentially (especially with segmented worms, although those aren't really external parasites) leave behind enough to regenerate, or create a wound that could easily infect. I've been unfortunate enough to see the aftermath of a goldfish with anchor worms at a chain pet store after an employee tried to forcibly extricate the worms... A terrible sight; the goldfish had torn swathes of skin around where the worms were, and the fish died soon. Although these parasites might be vastly different. I've always had better rates of success treating with formeldehyde and malachite green-based meds and aquarium salt instead of pulling them off.

 

[jjohnwm]

...I’d net the fish and pull it off/out. If it’s a parasite then removing it will cure it...

This! Especially on a decent-sized fish like this bichir seems to be, careful use of forceps should remove that ugly hanger-on easily. It will obviously leave a wound, which will likely heal without issue without any treatment necessary outside of clean water...but it won't heal if you leave that thing attached there.

...But removing an unknown external parasite by force can oftentimes do more harm than good...

I would replace the word "oftentimes" with something along the lines of "in extremely rare isolated instances". In the vast majority of cases, a careful but firm approach to removing the offending critter solves the problem. You aren't creating a wound...there's already a wound there, and it's got a big ugly worm in it. Remove the worm, and the wound will likely heal by itself with nothing more than clean water.

 

[fishmarket]

I tried giving it a firm but gentle pull with my plant tweezers but it didn't come off, even lifted the bichir off the gravel a bit but he was pretty chill about it. Feels/looks like flesh? I saw another thread where they think it was just loose membrane from an injury. Should I wait to see if it goes away in a few days? Maybe salt the tank for now?

 

[kno4te]

I tried giving it a firm but gentle pull with my plant tweezers but it didn't come off, even lifted the bichir off the gravel a bit but he was pretty chill about it. Feels/looks like flesh? I saw another thread where they think it was just loose membrane from an injury. Should I wait to see if it goes away in a few days? Maybe salt the tank for now?

Give it a few days and see what happens. I’d not salt for now.

 

[fishmarket]

Little hard to tell. What have you been feeding? Tilapia? I’d net the fish and pull it off/out. If it’s a parasite then removing it will cure it.

Yes they're mostly on shrimp and tilapia

 

[fishmarket]

It's been a few days and most of the worm looking things are gone, only one that got shorter remains.