Black Ghost Knife fish erratic behaviour

[chancefavours]

Hi,
my black ghost knife fish is approx 5 years old, and has always lived in a community tank. In the last 4 months or so, he/she has started being very active at the top of the tank, even swimming vertically with about 1/5th of his body out. He/she has even made contact with the glass lids.
Nothing has changed recently, still doing weekly 1/4 tank water changes, temp is steady at 25c, and ph sits close to neutral. Feeding twice a day with frozen blood worms, sinking pellets or flake.
I'm only going to take a guess, but maybe he has suddenly noticed his reflection ? Maybe becoming sexually mature or territorial ?
There's a pic attached, hopefully it works.

thanks

 

[Aquanero]

Could be any of the things you mentioned. Mine swine vertically from time to time. One thing is since these are"electric" fish check the tank for any stray electrical currents, heater etc. See if sothing is irritating it.

 

[chancefavours]

4ft x 1ft x 1ft tank
Tank mates - 5 clown loaches, 3 silver dollars, one dwarf gaurami, one skull creek rainbowfish. All from start.
PH - 6.6
Nitrite - 0ppm
Ammonia - 0ppm
Nitrate - 0ppm
No new medication / salts etc.

Tried turning heater off but no change (stray currents)