snakeheads flicking

[martin day]

hi my m8 has a two snakeheads (channa pulchra) which keep flicking alot i cant see anything visually on there skin like no white spot ,velvet,or excess slime
theyve been in the tank for about two months and have only just started doing it ,he`s done a water test and every thing reads normall
what else can it be ?

thanks

 

[martin day]

anyone?

 

[Lupin]

What test kit are you using? Which portion of the body do these fish always scrape on? Don't rule out the possibility of skin flukes, gill flukes and external parasites. Have you added anything new to the tank? If so, how long were those quarantined?